The following sections describe how to configure and use the Oracle Type 4 JDBC driver for DB2:
The driver classes for the Oracle Type 4 JDBC DB2 driver are as follows:
XA: weblogic.jdbcx.db2.DB2DataSource Non-XA: weblogic.jdbc.db2.DB2Driver
Use these driver classes when configuring a JDBC data source in your WebLogic Server domain.
The ManagedConnectionFactory class for the Informix resource adapter is:
com.weblogic.resource.spi.InformixManagedConnectionFactory
The connection URL format for the DB2 driver is:
jdbc:weblogic:db2://hostname:port[;property=value[;...]]
where:
hostname is the IP address or TCP/IP host name of the server to which you are connecting. See Using IP Addresses for details on using IP addresses.
Note:
Untrusted applets cannot open a socket to a machine other than the originating host.port is the number of the TCP/IP port.
property=value specifies connection properties. For a list of connection properties and their valid values, see DB2 Connection Properties.
For example:
DB2 UDB for Linux, UNIX, and Windows
jdbc:weblogic:db2://server1:50000;DatabaseName=jdbc;User=test;Password=secret
DB2 UDB for z/OS and iSeries
jdbc:weblogic:db2://server1:446;LocationName=Sample;User=test;Password=secret
Table 3-1 lists the JDBC connection properties supported by the DB2 driver, and describes each property. You can use these connection properties in a JDBC data source configuration in your WebLogic Server domain.
Note:
All connection property names are case-insensitive. For example, Password is the same as password. Required properties are noted as such. The data type listed for each connection property is the Java data type used for the property value in a JDBC data source.To specify a property, use the following form in the JDBC data source configuration: property=value.
Table 3-1 DB2 Connection Properties
| Property | Description |
|---|---|
|
AccountingInfo |
Accounting information to be stored in the database. This value sets the Data Type: String Valid Values: |
|
AddToCreateTable |
A string that is appended to the end of all Data Type: String Valid Values: |
|
AllowImplicitResultSetCloseForXA |
Note: Problems have been noted when using this mechanism. As a workaround, you should add The default is |
|
AlternateID |
Sets the default DB2 schema used by unqualified SQL identifiers to the specified value. For DB2 for Linux/UNIX/Windows and DB2 for iSeries, this property sets the value in the For DB2 for z/OS, this property sets the value in the Valid Values:
|
|
AlternateServers |
A list of alternate database servers that is used to failover new or lost connections, depending on the failover method selected. See the FailoverMode property for information about choosing a failover method. Data type: String Valid Values:
The server name ( Example: The following URL contains alternate server entries for server2 and server3. The alternate server entries contain the optional
Default: None |
|
ApplicationName |
The name of the application to be stored in the database. This value sets the Valid Values: Data Type: String Default is empty string. |
|
AuthenticationMethod |
Determines which authentication method the driver uses when establishing a connection. Valid Values: If If If If set to If The If the specified authentication method is not supported by the DB2 server, the connection fails and the driver throws an exception. The default is See Authentication for more information about using authentication with the DB2 driver. |
|
BatchPerformanceWorkaround |
The DB2 driver uses the native DB2 batch mechanism. This property determines whether certain restrictions are enforced to facilitate data conversions. Valid Values:
The default is See Batch Inserts and Updates for more information. Note: For data sources used as a JMS JDBC store that use the Oracle Type 4 JDBC driver for DB2, the |
|
BulkLoadBatchSize |
Provides a suggestion to the driver for the number of rows to load to the database at a time when bulk loading data. Performance can be improved by increasing the number of rows the driver loads at a time because fewer network round trips are required. Be aware that increasing the number of rows that are loaded also causes the driver to consume more memory on the client. NOTES:
Valid Values: Data Type: long |
|
CatalogIncludesSynonyms |
Determines whether synonyms are included in the result sets returned from the Data Type: If set to If set to See Performance Considerations for information about configuring this property for optimal performance. The default is |
|
CatalogOptions |
Determines which type of metadata information is included in result sets when an application calls DatabaseMetaData methods. Valid Values: 0 | 2 | 6 and the default value is 2. Data Type: int If 0, result sets do not contain synonyms. If 2, result sets contain synonyms that are returned from the following If 6, a hint is provided to the driver to emulate |
|
CatalogSchema |
The DB2 schema to use for catalog functions. The value must be the name of a valid DB2 schema. The default depends on the platform of the DB2 database. Valid Values: Data Type: String To improve performance, views of system catalog tables can be created in a schema other than the default catalog schema. Setting this property to a schema that contains views of the catalog tables allows the driver to use those views. To ensure that catalog methods function correctly, views for specific catalog tables must exist in the specified schema. The views that are required depend on your DB2 database. See Non-Default Schemas for Catalog Methods for the required views of catalog tables. See Performance Considerations for information about configuring this property for optimal performance. |
|
CharsetFor65535 |
The code page to use to convert character data stored as bit data in character columns ( |
|
ClientHostName |
The host name of the client machine to be stored in the database. This value sets the Valid Values: Data Type: String |
|
ClientUser |
The user ID to be stored in the database. This property sets the Valid Values: Data Type: String |
|
CodePageOverride |
A code page to be used to convert Data Type: String By default, the driver automatically determines which code page to use to convert |
|
CollectionId (DEPRECATED) |
This property is recognized for backward compatibility, but we recommend that you use the |
|
ConnectionRetryCount |
The number of times the driver retries connection attempts until a successful connection is established. Valid Values: 0 | Data Type: int If 0, the driver does not retry connections if a successful connection is not established on the driver's first attempt to create a connection. If set to x, the driver retries connection attempts the specified number of times. If a connection is not established during the retry attempts, the driver returns an exception that is generated by the last database server to which it tried to connect. The The default is 5. |
|
ConnectionRetryDelay |
The number of seconds the driver waits between connection retry attempts when Valid Values: 0 | If 0, the driver does not delay between retries. If The default is 1. |
|
ConvertNull |
Controls how data conversions are handled for null values. Valid Values: 0 | 1 Data Type: int If 0, the driver does not perform the data type check if the value of the column is null. This allows null values to be returned even though a conversion between the requested type and the column type is undefined. If 1 (the default), the driver checks the data type being requested against the data type of the table column storing the data. If a conversion between the requested type and column type is not defined, the driver generates an "unsupported data conversion" exception regardless of the data type of the column value. |
|
CreateDefaultPackage |
Determines whether the driver automatically creates required DB2 packages. Valid Values: If If For DB2 for Linux/UNIX/Windows, this property must be used in conjunction with the For DB2 for z/OS and DB2 for iSeries, DB2 packages are created in the collection or library specified by the For more information about creating DB2 packages, see Creating a DB2 Package. |
|
CurrentFunctionPath |
A list of DB2 schema names that are used to resolve unqualified function names and data type references in dynamically prepared SQL statements. It also is used to resolve unqualified stored procedure names that are specified in CALL statements. This property sets the CURRENT PATH register in the database. Valid Values: Data Type: String Default is null. |
|
Database |
An alias for the |
|
DatabaseName (REQUIRED) |
The name of the database to which you want to connect. This property is supported only for DB2 for Linux/UNIX/Windows. Note: This property is an alias for Valid Values: Data Type: StringAlias:
See also Database Connection Property. |
|
DynamicSections |
The maximum number of prepared statements that the DB2 driver can have open at any time. The value must be a positive integer. The default is 200. |
|
EnableBulkLoad |
Specifies whether the driver uses the native bulk load protocols in the database instead of the batch mechanism for batch inserts. Bulk load bypasses the data parsing that is usually done by the database, providing an additional performance gain over batch operations. This property allows existing applications with batch inserts to take advantage of bulk load without requiring changes to the application code. Valid Values: If If Data Type: boolean Default is |
|
EnableCancelTimeout |
Determines whether a cancel request sent by the driver as the result of a query timing out is subject to the same query timeout value as the statement it cancels. Valid Values: Data Type: boolean If If |
|
EncryptionMethod |
Determines whether data is encrypted and decrypted when transmitted over the network between the driver and database server. NOTE: Connection hangs can occur when the driver is configured for SSL and the database server does not support SSL. You may want to set a login timeout using the LoginTimeout property to avoid problems when connecting to a server that does not support SSL. Valid Values: If If If If
Data Type: String The default is |
|
FailoverGranularity |
Determines whether the driver fails the entire failover process or continues with the process if exceptions occur while trying to reestablish a lost connection. This property is ignored if Valid Values: If If If If Data Type: String Default is |
|
FailoverMode |
Specifies the type of failover method the driver uses. Valid Values: If If If NOTES:
Data Type: String Default is |
|
FailoverPreconnect |
Specifies whether the driver tries to connect to the primary and an alternate server at the same time. This property is ignored if Valid Values: If If NOTE: The Data Type: boolean Default is |
|
Grantee |
The name of the schema to which you want to grant Valid Values: Data Type: String IMPORTANT: Using a value other than Default is |
|
GrantExecute |
Determines which DB2 schema is granted Valid Values: Data Type: boolean If If The default is |
|
HostNameInCertificate |
Specifies a host name for certificate validation when SSL encryption is enabled (EncryptionMethod=SSL) and validation is enabled (ValidateServerCertificate=true). This property is optional and provides additional security against man-in-the-middle (MITM) attacks by ensuring that the server the driver is connecting to is the server that was requested. NOTES:
Valid Values: If If Data Type: String Default is empty string. |
|
ImportStatementPool |
Specifies the path and file name of the file to be used to load the contents of the statement pool. When this property is specified, statements are imported into the statement pool from the specified file. If the driver cannot locate the specified file when establishing the connection, the connection fails and the driver throws an exception. Valid Values: Data Type: String Default is empty string. |
|
InitializationString |
Specifies one or multiple SQL commands to be executed by the driver after it has established the connection to the database and has performed all initialization for the connection. If the execution of a SQL command fails, the connection attempt also fails and the driver throws an exception indicating which SQL command or commands failed. Valid Values: NOTE: Multiple commands must be separated by semicolons. In addition, if this property is specified in a connection URL, the entire value must be enclosed in parentheses when multiple commands are specified. Example: The following connection URL adds
NOTE: Setting the Data Type: String |
|
InsensitiveResultSetBufferSize |
Determines the amount of memory used by the driver to cache insensitive result set data. Valid Values -1 | 0 | Data Type: int If -1, the driver caches all insensitive result set data in memory. If the size of the result set exceeds available memory, an If 0, the driver caches all insensitive result set data in memory, up to a maximum of 2 GB. If the size of the result set data exceeds available memory, the driver pages the result set data to disk. Because result set data may be written to disk, the driver may have to reformat the data to write it correctly to disk. If x, where x is a positive integer that specifies the size (in KB) of the memory buffer used to cache insensitive result set data. If the size of the result set data exceeds the buffer size, the driver pages the result set data to disk. Because the result set data may be written to disk, the driver may have to reformat the data to write it correctly to disk. Specifying a buffer size that is a power of 2 results in more efficient memory use. The default is 2048 (KB) |
|
JavaDoubleToString |
Determines whether the driver uses its internal conversion algorithm or the JVM conversion algorithm when converting double or float values to string values. Valid Values: If If The default is |
|
JDBCBehavior |
Determines how the driver describes database data types that map to the following JDBC 4.0 data types: NCHAR, NVARCHAR, NLONGVARCHAR, NCLOB, and SQLXML. This property is applicable only when the application is using Java SE 6. Valid Values 0 | 1 Data Type: int If 0, the driver describes the data types as JDBC 4.0 data types when using Java SE 6. If 1, the driver describes the data types using JDBC 3.0-equivalent data types, regardless of JVM. This allows your application to continue using JDBC 3.0 types in a Java SE 6 environment. In addition, the JDBC 4.0 method Default is 1. |
|
KeyPassword |
Specifies the password that is used to access the individual keys in the keystore file when SSL is enabled ( This property is useful when individual keys in the keystore file have a different password than the keystore file. Valid Values: Data Type: String Default: None |
|
KeyStore |
Specifies the directory of the keystore file to be used when SSL is enabled ( This value overrides the directory of the keystore file that is specified by the NOTE: The keystore and truststore files can be the same file. Valid Values: Data Type: String Default: None |
|
KeyStorePassword |
Specifies the password that is used to access the keystore file when SSL is enabled ( This value overrides the password of the keystore file that is specified by the NOTE: The keystore and truststore files can be the same file. Valid Values: Data Type: String Default: None |
|
LoadBalancing |
Determines whether the driver uses client load balancing in its attempts to connect to the database servers (primary and alternate). You can specify one or multiple alternate servers by setting the Valid Values: If If Default: Data Type: boolean |
|
LocationName (REQUIRED) |
The name of the DB2 location that you want to access. For DB2 for z/OS, your system administrator can determine the name of your DB2 location using the following command: For DB2 for iSeries, your system administrator can determine the name of your DB2 location using the following command. The name of the database that is listed as *LOCAL is the value you should use for this property. For Valid Values: stringwhere string is the DB2 location. Default: None Data Type: String Alias: |
|
LoginTimeout |
The amount of time, in seconds, the driver waits for a connection to be established before returning control to the application and throwing a timeout exception. Valid Values 0 | If 0, the driver does not time out a connection request. If Default: 0 Data Type: int |
|
MaxPooledStatements |
The maximum number of pooled prepared statements for this connection. Setting Valid Values: 0 | If 0, the driver's internal prepared statement pooling is not enabled. If set to If the value set for this property is greater than the number of prepared statements that are used by the application, all prepared statements that are created by the application are cached. Because Example: If the value of this property is set to 20, the driver caches the last 20 prepared statements that are created by the application. Default: 0 Data Type: int Alias: |
|
MaxStatements |
An alias for the |
|
PackageCollection |
The name of the collection or library (group of packages) to which DB2 packages are bound. This property is ignored for DB2 for Linux/UNIX/Windows. Note: This property replaces the See Creating a DB2 Package for more information about creating DB2 packages. The default is NULLID. |
|
PackageOwner |
The owner to be used for any DB2 packages that are created. See Creating a DB2 Package for more information about creating DB2 packages. The default is NULL. Data Type: String |
|
Password |
A case-sensitive password used to connect to your DB2 database. A password is required only if security is enabled on your database. If so, contact your system administrator to get your password. Valid Values: Default: None Data Type: String |
|
PortNumber |
The TCP port on which the database server listens for connections. The default is 50000. |
|
ProgramID |
The product and version information of the driver on the client to be stored in the database. This value sets the Valid Values
Example: DDJ04100 Default: empty stringData Type: String |
|
QueryTimeout |
Positive integer, -1, or zero (0). Sets the default query timeout (in seconds) for all statements created by a connection. If set to a positive integer, the driver uses the value as the default timeout for any statement created by the connection. To override the default timeout value set by this connection option, call the If set to -1, the query timeout functionality is disabled. The driver silently ignores calls to the If set to 0 (the default), the default query timeout is infinite (the query does not time out). The default is 0. |
|
ReplacePackage |
Determines whether the current bind process will replace the existing DB2 packages used by the driver. For DB2 for Linux/UNIX/Windows, this property must be used in conjunction with the Valid Values: If If Default: Data Type: boolean |
|
ResultSetMetaDataOptions |
The DB2 driver can return table name information in the ResultSet metadata for Select statements if your application requires that information. Valid Values 0 | 1 If set to 0 (the default) and the If set to 1 and the For information about configuring this property for optimal performance, see Performance Considerations. The default is 0. Data Type: int |
|
SecurityMechanism (DEPRECATED) |
This property is recognized for backward compatibility, but we recommend that you use the |
|
SendStreamAsBlob |
Determines whether binary stream data that is less than 32K bytes is sent to the database as Long Varchar for Bit Data or Blob data. Binary streams that are larger than 32K bytes can only be inserted into a Blob column. The driver always sends binary stream data larger than 32K bytes to the database as Blob data. Valid Values: If If See Performance Considerations for information about configuring this property for optimal performance. The default is Data Type: boolean |
|
ServerName (REQUIRED) |
Specifies either the IP address in IPv4 or IPv6 format, or the server name (if your network supports named servers) of the database server. This property is supported only for data source connections. Valid Values: Example: 122.23.15.12 or DB2ServerDefault: None Data Type: String |
|
SpyAttributes |
Enables DataDirect Spy to log detailed information about calls that are issued by the driver on behalf of the application. Spy is not enabled by default. Valid Values:
Default: None Data Type: String |
|
StripNewlines |
Specifies whether new-line characters in a SQL statement are sent to the DB2 server. If you know that the SQL statements used in your application do not contain newline characters, instructing the driver to not remove them eliminates parsing by the DB2 server and improves performance. Valid Values: If If Default: Data Type: boolean See Performance Considerations for information about configuring this property for optimal performance. |
|
TrustStore |
Specifies the directory of the truststore file to be used when SSL is enabled using the This property is ignored if Valid Values: Defaul:t None Data Type: String |
|
TrustStorePassword |
Specifies the password that is used to access the truststore file when SSL is enabled using the EncryptionMethod property and server authentication is used. The truststore file contains a list of the Certificate Authorities (CAs) that the client trusts. This value overrides the password of the truststore file that is specified by the This property is ignored if Valid Values: Default: NoneData Type: String |
|
UseCurrentSchema |
Specifies whether results are restricted to the tables and views in the current schema if a Valid Values: If If See Performance Considerations for information about configuring this property for optimal performance. The default is false. Data Type: boolean |
|
User |
The case-sensitive user name used to connect to the DB2 database. Valid Values: Data Type: String |
|
ValidateServerCertificate |
Determines whether the driver validates the certificate that is sent by the database server when SSL encryption is enabled (EncryptionMethod=SSL). When using SSL server authentication, any certificate that is sent by the server must be issued by a trusted Certificate Authority (CA). Allowing the driver to trust any certificate that is returned from the server even if the issuer is not a trusted CA is useful in test environments because it eliminates the need to specify truststore information on each client in the test environment. Valid Values: If If NOTE: Truststore information is specified using the Default: Data Type: boolean |
|
WithHoldCursors |
Determines whether the cursor stays open on commit—either DB2 leaves all cursors open (Preserve cursors) or closes all open cursors (Delete cursors) after a commit. Rolling back a transaction closes all cursors regardless of how this property is specified. Valid Values true | false If If The default is Data Type: boolean |
|
XMLDescribeType |
Determines whether the driver maps XML data to the CLOB or BLOB data type. Valid Values: If If See Returning and Inserting/Updating XML Data for more information. The default is Data Type: String |
Setting the following connection properties for the DB2 driver as described in the following list can improve performance for your applications:
The DatabaseMetaData.getColumns method is often used to determine characteristics about a table, including the synonym, or alias, associated with a table. If your application accesses DB2 v7.x for Linux/UNIX/Windows, DB2 for z/OS, or DB2 for iSeries and your application does not use database table synonyms, the driver can improve performance by ignoring this information. The driver always returns synonyms for the DatabaseMetaData.getColumns() method when accessing DB2 v8.x and higher for Linux/UNIX/Windows.
Retrieving synonym information is expensive. If your application does not need to return this information, the driver can improve performance. Default driver behavior is to include synonyms in the result set of calls to the following DatabaseMetaData methods: getColumns(), getExportedKeys(), getFunctionColumns(), getFunctions(), getImportedKeys(), getIndexInfo(), getPrimaryKeys(), getProcedureColumns(), and getProcedures(). If your application needs to return synonyms for getColumns() calls, the driver can emulate getColumns() calls using the ResultSetMetaData object instead of querying database catalogs for the column information. Using emulation can improve performance because the SQL statement formulated by the emulation is less complex than the SQL statement formulated using getColumns().
To improve performance, views of system catalog tables can be created in a catalog schema other than the default. The DB2 driver can access the views of catalog tables if this property is set to the name of the schema containing the views. The default catalog schema is SYSCAT for DB2 for Linux/UNIX/Windows, SYSIBM for DB2 for z/OS, and QSYS2 for DB2 for iSeries.
To ensure that catalog methods function correctly, views for specific catalog tables must exist in the specified schema. The views that are required depend on your DB2 database. See Non-Default Schemas for Catalog Methods for views for catalog tables that must exist in the specified schema.
For batch inserts, the driver can use native bulk load protocols instead of the batch mechanism. Bulk load bypasses the data parsing usually done by the database, providing an additional performance gain over batch operations. Set this property to true to allow existing applications with batch inserts to take advantage of bulk load without requiring changes to the code.
Data encryption may adversely affect performance because of the additional overhead (mainly CPU usage) required to encrypt and decrypt data.
To improve performance when using scroll-insensitive result sets, the driver can cache the result set data in memory instead of writing it to disk. By default, the driver caches 2 MB of insensitive result set data in memory and writes any remaining result set data to disk. Performance can be improved by increasing the amount of memory used by the driver before writing data to disk or by forcing the driver to never write insensitive result set data to disk. The maximum cache size setting is 2 GB.
To improve performance, the driver's own internal prepared statement pooling should be enabled when the driver does not run from within an application server or from within another application that does not provide its own prepared statement pooling. When the driver's internal prepared statement pooling is enabled, the driver caches a certain number of prepared statements created by an application. For example, if the MaxPooledStatements property is set to 20, the driver caches the last 20 prepared statements created by the application. If the value set for this property is greater than the number of prepared statements used by the application, all prepared statements are cached.
If the large binary objects you insert or update are stored as Blobs, performance can be improved by sending the binary stream as Blob data. In this case, this property should be set to true.
If you know that the SQL statements used in your application do not contain newline characters, the driver can improve performance by omitting the parsing required to remove them.
If your application needs to access tables and views owned only by the current user, performance of your application can be improved by setting this property to true. When this property is set to true, the driver returns only tables and views owned by the current user when executing getTables() and getColumns() methods. Setting this property to true is equivalent to passing the user ID used on the connection as the schemaPattern argument to the getTables() or getColumns() call.
When connecting to a DB2 database running on AS/400, you must set the locationName property:
Obtain the "Relational Database" value by executing the WRKRDBDIRE command on AS/400.
You should see output similar to the following:
,Relational,,Remote,Option,,Database,,Location,,Text, , ,, , ,,S10B757B,,*LOCAL ,, ,
In the Java client, set up the Properties object with "user" and "password" DB2 connection properties (see DB2 Connection Properties).
In Driver.connect(), specify the following string and the Properties object as parameters:
jdbc:weblogic:db2://<Host>:<Port>;LocationName=RelationalDatabaseName
In this example, RelationalDatabaseName is the value of Database obtained from the result of running the WRKRDBDIRE command.
The following is an excerpt of the Java client:
...
Properties props = new Properties();
props.put("user", user);
props.put("password", password);
...
myDriver = (Driver)Class.forName("weblogic.jdbc.db2.DB2Driver").newInstance();
conn = myDriver.connect("jdbc:weblogic:db2://10.1.4.1:446;LocationName=S10B757B", props);
stmt = conn.createStatement();
stmt.execute("select * from MYDATABASE.MYTABLE");
rs = stmt.getResultSet();
...
A DB2 package is a control structure on the DB2 server produced during program preparation that is used to execute SQL statements. The DB2 driver automatically creates all DB2 packages required at connection time. If a package already exists, the driver uses the existing package to establish a connection.
Note:
The initial connection may take a few minutes because of the number and size of the packages that must be created for the connection. Subsequent connections do not incur this delay.When the driver has completed creating packages, it writes the following message to the standard output: DB2 packages created.
By default, DB2 packages created by the DB2 driver contain 200 dynamic sections and are created in the NULLID collection (or library). In most cases, you do not need to create DB2 packages because the DB2 driver automatically creates them at connection time. If required, you can create DB2 packages in either of the following ways:
Manually force the DB2 driver to create a package using the WebLogic Server dbping utility. See Creating a DB2 Package Using dbping.
Automatically create a package by setting specific connection properties in the connection URL or data source. See Creating a DB2 Package Using Connection Properties.
Note:
Your user ID must have CREATE PACKAGE privileges on the database, or your database administrator must create packages for you.Your user ID (the user ID listed in the JDBC data source configuration) must be the owner of the package.
The user ID creating the DB2 packages must have BINDADD privileges on the database. Consult with your database administrator to ensure that you have the correct privileges.
To create a package on the DB2 server with the Oracle Type 4 JDBC DB2 driver, you can use the WebLogic Server dbping utility. The dbping utility is used to test the connection between your client machine and a DBMS via a JDBC driver. Because the Oracle Type 4 JDBC DB2 driver automatically creates a DB2 package if one does not already exist, running this utility creates a default DB2 package on the DB2 server.
For details about using the dbping utility to create a DB2 package, see "Creating a DB2 Package with dbping" in Command Reference for Oracle WebLogic Server.
You can create a DB2 package automatically by specifying specific connection properties in the initial connection URL. Table 3-2 lists the connection properties you should use in your initial connection URL when you create a DB2 package:
Note:
This method is not recommended for use with WebLogic Server JDBC data sources because every connection in the data source uses the same URL and connection properties. When a JDBC data source with multiple connections is created, the package would be recreated when each database connection is created.Table 3-2 Connection Properties for an Initial Connection URL When Creating DB2 Packages
| Property | Database |
|---|---|
|
PackageCollection=collection_name, (where |
DB2 for z/OS and iSeries |
|
CreateDefaultPackage=true |
DB2 for Linux/UNIX/Windows, z/OS, and iSeries |
|
ReplacePackage=true |
DB2 for Linux/UNIX/Windows |
|
DynamicSections=x, (where x is a positive integer) |
DB2 for Linux/UNIX/Windows, z/OS, and iSeries |
Using CreateDefaultPackage=TRUE creates a package with a default name. If you use CreateDefaultPackage=TRUE, and you do not specify a CollectionId, the NULLID CollectionId is created.
Note:
To create new DB2 packages on DB2 for Linux/UNIX/Windows, you must useReplacePackage=true in conjunction with CreateDefaultPackage=true. If a DB2 package already exists, it will be replaced when ReplacePackage=true.The following URL creates DB2 packages with 400 dynamic sections. If any DB2 packages already exist, they will be replaced by the new ones being created.
jdbc:weblogic:db2://server1:50000;DatabaseName=SAMPLE; CreateDefaultPackage=TRUE;ReplacePackage=TRUE;DynamicSections=400
A dynamic section is the actual executable object that contains the logic needed to satisfy a dynamic SQL request. These sections are used for handles and prepared statements and the associated result sets.
In some cases, you may need to create DB2 packages with more than the default number of dynamic sections (200). Consider the following information if your application requires DB2 packages with a large number of dynamic sections:
Creating DB2 packages with a large number of dynamic sections may exhaust certain server resources. In particular, you may need to increase the database parameter PCKCACHE_SZ to allow the larger packages to be created.
The creation of more dynamic sections will slow down the initial creation of the DB2 package.
Using DB2 packages with a large number of dynamic sections may impact application performance. If a small number of sections are in use at one time, there will be no impact on the application. If a large number of sections are in use at one time, the performance of the application may decrease because the database will expend resources to check all open sections for locks.
As the number of open sections increases, so does the likelihood that a deadlock situation may occur.
If your application is mostly executing select statements, it is best to operate in the default mode of automatically committing the database. Dynamic sections are not freed in the DB2 package until the database is committed even if the statements are closed in the application. In this mode the database will commit every time a SQL statement is executed and free all of the sections that were opened. If you need to operate in a manual commit mode, then it is advisable to commit the database as often as possible to ensure that all server resources are freed in a timely manner.
Statements cached in the WebLogic Server prepared statement cache will keep sections in use so that the prepared statements can be reused.
The DB2 server has a limit on dynamic sections. It is possible to try to create more sections than the server will allow you to create.
Table 3-3 lists the data types supported by the DB2 driver and how they are mapped to JDBC data types.
| DB2 Data Type | JDBC Data Type |
|---|---|
|
BigintFoot 1 |
BIGINT |
|
BinaryFoot 2 |
BINARY |
|
BlobFoot 3 |
BLOB |
|
Char |
CHAR |
|
Char for Bit Data |
BINARY |
|
Clob |
CLOB NOTE: If |
|
Date |
DATE |
|
DBClobFoot 4 |
CLOB |
|
DecfloatFoot 5 |
DECIMAL |
|
Decimal |
DECIMAL |
|
Double |
DOUBLE |
|
Float |
FLOAT |
|
Graphic |
CHAR NOTE: If |
|
Integer |
INTEGER |
|
Long Varchar |
LONGVARCHAR |
|
Long Varchar for Bit Data |
LONGVARBINARY |
|
Long Vargraphic |
LONGVARCHAR NOTE: If |
|
Numeric |
NUMERIC |
|
Real |
REAL |
|
RowidFoot 6 |
VARBINARY |
|
Smallint |
SMALLINT |
|
Time |
TIME |
|
Timestamp |
TIMESTAMP |
|
Varbinary |
VARBINARY |
|
Varchar |
VARCHAR |
|
Varchar for Bit Data |
VARBINARY |
|
Vargraphic |
VARCHAR NOTE: If |
|
XML |
CLOB NOTE: If |
Footnote 1 Supported only for DB2 v8.1 and v 8.2 for Linux/UNIX/Windows.
Footnote 2 Supported only for DB2 v8.1 and v 8.2 for Linux/UNIX/Windows.
Footnote 3 Supported only for DB2 v8.1 and v 8.2 for Linux/UNIX/Windows, DB2 for z/OS, and DB2 V5R2 and V5R3 for iSeries (see Large Object (LOB) Support).
Footnote 4 Supported only for DB2 v8.1 and v 8.2 for Linux/UNIX/Windows, DB2 7.x v8.1, and v8.2 for z/OS, and DB2 V5R2 and V5R3 for iSeries (see Large Object (LOB) Support).
Footnote 5 Supported only for DB2 v8.1 and v 8.2 for Linux/UNIX/Windows, DB2 7.x v8.1, and v8.2 for z/OS, and DB2 V5R2 and V5R3 for iSeries (see Large Object (LOB) Support).
Footnote 6 Supported only for DB2 for z/OS, and DB2 V5R2 and V5R3 for iSeries.
See Large Object (LOB) Support for more information about the Blob, Clob, and DBClob data types. See Returning and Inserting/Updating XML Data for more information about the XML data type.See Appendix B, "GetTypeInfo" for more information about data types.
For DB2 V9.1 for Linux/UNIX/Windows, the DB2 driver supports the XML data type. By default, the driver maps the XML data type to the JDBC CLOB data type, but you can choose to map the XML data type to the BLOB data type by setting the XMLDescribeType connection property to a value of blob.
The driver can return XML data as character or binary data. For example, given a database table defined as:
CREATE TABLE xmlTable (id int, xmlCol xml NOT NULL)
and the following code:
String sql="SELECT xmlCol FROM xmlTable"; ResultSet rs=stmt.executeQuery(sql);
The driver returns the XML data from the database as character or binary data depending on the setting of the XMLDescribeType property. By default, the driver maps the XML data type to the JDBC CLOB data type. If the following connection URL mapped the XML data type to the BLOB data type, the driver would return the XML data as binary data instead of character data:
jdbc:weblogic:db2://server1:50000;DatabaseName=jdbc;User=test; Password=secret;XMLDescribeType=blob
When XMLDescribeType=clob, XML data is returned as character data. The result set column is described with a column type of CLOB and the column type name is xml.
When XMLDescribeType=clob, your application can use the following methods to return data stored in XML columns as character data:
ResultSet.getString() ResultSet.getCharacterStream() ResultSet.getClob() CallableStatement.getString() CallableStatement.getClob()
The driver converts the XML data returned from the database server from the UTF-8 encoding used by the database server to the UTF-16 Java String encoding.
Your application can use the following method to return data stored in XML columns as ASCII data:
ResultSet.getAsciiStream()
The driver converts the XML data returned from the database server from the UTF-8 encoding to the ISO-8859-1 (latin1) encoding.
Note:
The conversion caused by using the getAsciiStream() method may create XML that is not well-formed because the content encoding is not the default encoding and does not contain an XML declaration specifying the content encoding. Do not use the getAsciiStream() method if your application requires well-formed XML.When XMLDescribeType=blob, your application should not use any of the methods for returning character data described in this section. In this case, the driver applies the standard JDBC character-to-binary conversion to the data, which returns the hexadecimal representation of the character data.
When XMLDescribeType=blob, the driver returns XML data as binary data. The result set column is described with a column type of BLOB and the column type name is xml.
When XMLDescribeType=blob, your application can use the following methods to return XML data as binary data:
ResultSet.getBytes() ResultSet.getBinaryStream() ResultSet.getBlob() ResultSet.getObject() CallableStatement.getBytes() CallableStatement.getBlob() CallableStatement.getObject()
The driver does not apply any data conversions to the XML data returned from the database server. These methods return a byte array or binary stream that contains the XML data encoded as UTF-8.
When XMLDescribeType=clob, your application should not use any of the methods for returning binary data described in this section. In this case, the driver applies the standard JDBC binary-to-character conversion to the data, which returns the hexadecimal representation of the binary data.
The driver can insert or update XML data as character or binary data regardless of the setting of the XMLDescribeType connection property.
Your application can use the following methods to insert or update XML data as character data:
PreparedStatement.setString() PreparedStatement.setCharacterStream() PreparedStatement.setClob() PreparedStatement.setObject() ResultSet.updateString() ResultSet.updateCharacterStream() ResultSet.updateClob() ReultSet.updateObject()
The driver converts the character representation of the data to the XML character set used by the database server and sends the converted XML data to the server. The driver does not parse or remove any XML processing instructions.
Your application can update XML data as ASCII data using the following methods:
PreparedStatement.setAsciiStream() ResultSet.updateAsciiStream()
The driver interprets the data supplied to these methods using the ISO-8859-1 (latin 1) encoding. The driver converts the data from ISO-8859-1 to the XML character set used by the database server and sends the converted XML data to the server.
Your application can use the following methods to insert or update XML data as binary data:
PreparedStatement.setBytes() PreparedStatement.setBinaryStream() PreparedStatement.setBlob() PreparedStatement.setObject() ResultSet.updateBytes() ResultSet.updateBinaryStream() ResultSet.updateBlob() ReultSet.updateObject()
The driver does not apply any data conversions when sending XML data to the database server.
Authentication protects the identity of the user so that user credentials cannot be intercepted by malicious hackers when transmitted over the network. See Authentication for an overview.
The DB2 driver supports the following methods of authentication:
User ID/password authentication authenticates the user to the database using a database user name and password. Depending on the method you specify, the driver passes one of the following sets of credentials to the DB2 database server for authentication:
Encrypted user ID and password
User ID in clear text and an encrypted password
Both user ID and password in clear text
Kerberos authentication uses Kerberos, a trusted third-party authentication service, to verify user identities. Kerberos authentication can take advantage of the user name and password maintained by the operating system to authenticate users to the database or use another set of user credentials specified by the application.
This method requires knowledge of how to configure your Kerberos environment and supports Windows Active Directory Kerberos and MIT Kerberos.
Client authentication uses the user ID of the user logged onto the system on which the driver is running to authenticate the user to the database. The DB2 database server relies on the client to authenticate the user and does not provide additional authentication.
Note:
Because the database server does not authenticate the user when client authentication is used, use this method of authentication if you can guarantee that only trusted clients can access the database server.The driver's AuthenticationMethod connection property controls which authentication mechanism the driver uses when establishing connections. See Using the AuthenticationMethod Property for information about setting the value for this property.
The AuthenticationMethod connection property controls which authentication mechanism the driver uses when establishing connections.
When AuthenticationMethod=kerberos, the driver uses Kerberos authentication when establishing a connection. The driver ignores any values specified by the User property and Password properties.
When AuthenticationMethod=encryptedUIDPassword, AuthenticationMethod=encryptedPassword, or AuthenticationMethod=clearText (the default), the driver uses user ID/password authentication when establishing a connection. The User property provides the user ID. The Password property provides the password. The set of credentials that are passed to the DB2 server depend on the specified value:
When AuthenticationMethod=encryptedUIDPassword, an encrypted user ID and encrypted password are sent to the DB2 server for authentication.
When AuthenticationMethod=encryptedPassword, a user ID in clear text and an encrypted password are sent to the DB2 server for authentication.
When AuthenticationMethod=clearText, both a user ID and a password are sent in clear text to the DB2 server for authentication.
If any of these values are set, the driver also can use data encryption by setting the EncryptionMethod property.
When AuthenticationMethod=client, the driver uses the user ID of the user logged onto the system on which the driver is running when establishing a connection. The DB2 database server relies on the client to authenticate the user and does not provide additional authentication. The driver ignores any values specified by the User property and Password properties.
To configure user ID/password authentication:
Set the AuthenticationMethod property to encryptedUIDPassword, encryptedPassword, or clearText (the default). See Using the AuthenticationMethod Property for more information about setting a value for this property.
Set the User property to provide the user ID.
Set the Password property to provide the password.
This section provides requirements and instructions for configuring Kerberos authentication for the DB2 driver.
Verify that your environment meets the requirements listed in Table 3-4 before you configure the driver for Kerberos authentication.
Table 3-4 Kerberos Authentication Requirements for the DB2 Driver
| Component | Requirements |
|---|---|
|
Database server |
The database server must be running one of the following database versions:
|
|
Kerberos server |
The Kerberos server is the machine where the user IDs for authentication are administered. The Kerberos server is also the location of the Kerberos KDC.
|
|
Client |
J2SE 1.4.2 or higher must be installed. |
During installation of the WebLogic Server JDBC drivers, the following files required for Kerberos authentication are installed in the WL_HOME\server\lib folder, where WL_HOME is the directory in which you installed WebLogic Server:
krb5.conf is a Kerberos configuration file containing values for the Kerberos realm and the KDC name for that realm. WebLogic Server installs a generic file that you must modify for your environment.
JDBCDriverLogin.conf file is a configuration file that specifies which Java Authentication and Authorization Service (JAAS) login module to use for Kerberos authentication. This file is configured to load automatically unless the java.security.auth.login.config system property is set to load another configuration file. You can modify this file, but the driver must be able to find the JDBC_DRIVER_01 entry in this file or another specified login configuration file to configure the JAAS login module. Refer to your J2SE documentation for information about setting configuration options in this file.
To configure the driver:
Set the AuthenticationMethod property to kerberos. See Using the AuthenticationMethod Property for more information about setting a value for this property.
Modify the krb5.conf file to contain your Kerberos realm name and the KDC name for that Kerberos realm by editing the file with a text editor or by specifying the system properties, java.security.krb5.realm and java.security.krb5.kdc.
Note:
If using Windows Active Directory, the Kerberos realm name is the Windows domain name and the KDC name is the Windows domain controller name.For example, if your Kerberos realm name is XYZ.COM and your KDC name is kdc1, your krb5.conf file would look like this:
[libdefaults]
default_realm = XYZ.COM
[realms]
XYZ.COM = {
kdc = kdc1
}
If the krb5.conf file does not contain a valid Kerberos realm and KDC name, the following exception is thrown:
Message:[OWLS][DB2 JDBC Driver]Could not establish a connection using integrated security: No valid credentials provided
The krb5.conf file installed with the WebLogic JDBC drivers is configured to load automatically unless the java.security.krb5.conf system property is set to point to another Kerberos configuration file.
If using Kerberos authentication with a Security Manager on a Java 2 Platform, you must grant security permissions to the application and driver. See Permissions for Kerberos Authentication for an example.
By default, when Kerberos authentication is used, the DB2 driver takes advantage of the user name and password maintained by the operating system to authenticate users to the database. By allowing the database to share the user name and password used for the operating system, users with a valid operating system account can log into the database without supplying a user name and password.
There may be times when you want the driver to use another set of user credentials. For example, many application servers or Web servers act on behalf of the client user logged on the machine on which the application is running, rather than the server user.
If you want the driver to use user credentials other than the server user's operating system credentials, include code in your application to obtain and pass a javax.security.auth.Subject used for authentication as shown in the following example.
import javax.security.auth.Subject;
import javax.security.auth.login.LoginContext;
import java.sql.*;
// The following code creates a javax.security.auth.Subject instance
// used for authentication. Refer to the Java Authentication
// and Authorization Service documentation for details on using a
// LoginContext to obtain a Subject.
LoginContext lc = null;
Subject subject = null;
try {
lc = new LoginContext("JaasSample", new TextCallbackHandler());
lc.login();
subject = lc.getSubject();
}
catch (Exception le) {
... // display login error
}
// This application passes the javax.security.auth.Subject
// to the driver by executing the driver code as the subject
Connection con =
(Connection) Subject.doAs(subject, new PrivilegedExceptionAction() {
public Object run() {
Connection con = null;
try {
Class.forName("com.ddtek.jdbc.db2.DB2Driver");
String url = "jdbc:weblogic:db2://myServer:50000;
DatabaseName=jdbc";
con = DriverManager.getConnection(url);
}
catch (Exception except) {
... //log the connection error
Return null;
}
return con;
}
});
// This application now has a connection that was authenticated with
// the subject. The application can now use the connection.
Statement stmt = con.createStatement();
String sql = "select * from employee";
ResultSet rs = stmt.executeQuery(sql);
... // do something with the results
To use Kerberos authentication, the application user first must obtain a Kerberos Ticket Granting Ticket (TGT) from the Kerberos server. The Kerberos server verifies the identity of the user and controls access to services using the credentials contained in the TGT.
If the application uses Kerberos authentication from a Windows client, the application user does not need to explicitly obtain a TGT. Windows Active Directory automatically obtains a TGT for the user.
If the application uses Kerberos authentication from a UNIX or Linux client, the user must explicitly obtain a TGT. To explicitly obtain a TGT, the user must log onto the Kerberos server using the kinit command. For example, the following command requests a TGT from the server with a lifetime of 10 hours, which is renewable for 5 days:
kinit -l 10h -r 5d user
where user is the application user.
Refer to your Kerberos documentation for more information about using the kinit command and obtaining TGTs for users.
Set the AuthenticationMethod property to client. See Using the AuthenticationMethod Property for more information about setting a value for this property.
The DB2 driver now supports SSL encryption for DB2 V5R3 and higher for iSeries. SSL secures the integrity of your data by encrypting information and providing authentication. The DB2 driver supports both SSL server authentication and SSL client authentication.
See SSL Encryption for more information.
Note:
Data encryption may adversely affect performance because of the additional overhead (mainly CPU usage) required to encrypt and decrypt data.Note:
Connection hangs can occur when the driver is configured for SSL and the database server does not support SSL. You may want to set a login timeout using the LoginTimeout property to avoid problems when connecting to a server that does not support SSL.To configure SSL encryption:
Set the EncryptionMethod property to SSL.
Specify the location and password of the truststore file used for SSL server authentication. Either set the TrustStore and TrustStore properties or their corresponding Java system properties (javax.net.ssl.trustStore and javax.net.ssl.trustStorePassword, respectively).
To validate certificates sent by the database server, set the ValidateServerCertificate property to true.
Optionally, set the HostNameInCertificate property to a host name to be used to validate the certificate. The HostNameInCertificate property provides additional security against man-in-the-middle (MITM) attacks by ensuring that the server the driver is connecting to is the server that was requested.
If your database server is configured for SSL client authentication, configure your keystore information:
Specify the location and password of the keystore file. Either set the KeyStore and KeyStorePassword properties or their corresponding Java system properties (javax.net.ssl.keyStore and javax.net.ssl.keyStorePassword, respectively).
If any key entry in the keystore file is password-protected, set the KeyPassword property to the key password.
To ensure that catalog methods function correctly when the CatalogSchema property is set to a schema other than the default schema, views for the catalog tables listed in Table 3-5 must exist in the specified schema. The views that are required depend on your DB2 database.
Table 3-5 Catalog Tables for DB2
| Database | Catalog Tables |
|---|---|
|
DB2 for Linux/UNIX/Windows |
SYSCAT.TABLES SYSCAT.COLUMNS SYSCAT.PROCEDURES SYSCAT.PROCPARAMS SYSCAT.COLAUTH SYSCAT.TABAUTH SYSCAT.KEYCOLUSE SYSCAT.INDEXES SYSCAT.INDEXCOLUSE SYSCAT.REFERENCES SYSCAT.SYSSCHEMATA SYSCAT.TYPEMAPPINGS SYSCAT.DBAUTH |
|
DB2 for z/OS |
SYSIBM.SYSTABCONST SYSIBM.SYSTABLES SYSIBM.SYSSYNONYMS SYSIBM.SYSCOLUMNS SYSIBM.SYSPROCEDURES SYSIBM.SYSROUTINES SYSIBM.SYSPARMS SYSIBM.SYSCOLAUTH SYSIBM.SYSTABAUTH SYSIBM.SYSKEYS SYSIBM.SYSINDEXES SYSIBM.SYSRELS SYSIBM.SYSFOREIGNKEYS SYSIBM.SYSSCHEMAAUTH SYSIBM.SYSDBAUTH |
|
DB2 for iSeries |
QSYS2.SYSCST QSYS2.SYSKEYCST QSYS2.SYSPROCS QSYS2.SYSPARMS QSYS2.SYSTABLES QSYS2.SYSSYNONYM QSYS2.SYSCOLUMNS QSYS2.SQLTABLEPRIVILEGES QSYS2.SYSKEYS QSYS2.SYSINDEXES QSYS2.SYSREFCSTS |
The DB2 driver supports reauthentication for the following databases:
DB2 V9.1 and higher for Linux/UNIX/Windows. The user performing the switch must have been granted the database SETSESSIONUSER permission.
DB2 v8.1.4 and higher for Linux/UNIX/Windows. The user performing the switch must have been granted the SYSADM permission.
Before performing reauthentication, applications must ensure that any statements or result sets created as one user are closed before switching the connection to another user.
Your application can use the setCurrentUser() method in the ExtConnection interface to switch a user on a connection.
The setCurrentUser() method accepts driver-specific reauthentication options. The options supported for the DB2 driver are:
CURRENT_SCHEMA
Specifies the name of the current schema. The value must be a valid DB2 schema name.
If the setCurrentUser() method is called and this option is not specified or the value is set to #USER#, the schema is switched to the schema of the current user. If the setCurrentUser() method is called and this option is specified as an empty string, only the user is switched; the schema is not switched.
CURRENT_PATH
Specifies the current path for the database to use when locating stored procedures and functions. The value must be a valid path name for the DB2 CURRENT PATH special register.
If the setCurrentUser() method is called and this option is not specified or the value is set to #USER#, the path is switched to the path of the current user. If the setCurrentUser() method is called and this option is specified as an empty string, only the user is switched; the path is not switched.
See Appendix C, "SQL Escape Sequences for JDBC" for information about SQL escape sequences supported by the DB2 driver.
The DB2 driver supports the isolation levels listed in Table 3-6. JDBC isolation levels are mapped to the appropriate DB2 transaction isolation levels as shown. The default isolation level is Read Committed.
Table 3-6 Supported Isolation Levels
| JDBC Isolation Level | DB2 Isolation Level |
|---|---|
|
None |
No CommitFoot 1 |
|
Read Committed |
Cursor Stability |
|
Read Uncommitted |
Uncommitted Read |
|
Repeatable Read |
Read Stability |
|
Serializable |
Repeatable Read |
Footnote 1 Supported for DB2 iSeries versions that do not enable journaling.
The DB2 driver supports scroll-insensitive result sets and updatable result sets.
Note:
When the DB2 driver cannot support the requested result set type or concurrency, it automatically downgrades the cursor and generates one or more SQLWarnings with detailed information.To use distributed transactions through JTA with the DB2 driver, you must use one of the following database versions:
DB2 v8.x and higher for Linux/UNIX/Windows
DB2 V5R4 for iSeries
DB2 v9.1 for z/OS.
Retrieving and updating Blobs is supported by the DB2 driver with the following databases:
DB2 v8.x and higher for Linux/UNIX/Windows
DB2 for z/OS
DB2 V5R2 and higher for iSeries
Retrieving and updating Clobs is supported by the DB2 driver with all supported DB2 databases. The DB2 driver supports Clobs up to a maximum of 2 GB with the following DB2 databases:
DB2 v8.x and higher for Linux/UNIX/Windows
DB2 for z/OS
DB2 V5R2 and higher for iSeries
The DB2 driver supports retrieving and updating Clobs up to a maximum of 32 KB with all other supported DB2 databases.
Retrieving and updating DBClobs is supported by the DB2 driver with the following databases:
DB2 v8.x and higher for Linux/UNIX/Windows
DB2 for z/OS
DB2 V5R2 and higher for iSeries
The DB2 driver uses the native DB2 batch mechanism. By default, the methods used to set the parameter values of a batch performed using a PreparedStatement must match the database data type of the column with which the parameter is associated.
DB2 servers do not perform implicit data conversions, so specifying parameter values that do not match the column data type causes the DB2 server to generate an error. For example, to set the value of a Blob parameter using a stream or byte array when the length of the stream or array is less than 32 KB, you must use the setObject() method and specify the target JDBC type as BLOB; you cannot use the setBinaryStream() or setBytes() methods.
To remove the method-type restriction, set the BatchPerformanceWorkaround property to true. For example, you can use the setBinaryStream() or setBytes() methods to set the value of a Blob parameter regardless of the length of the stream or array; however, the parameter sets may not be executed in the order they were specified. Performance may be decreased because the driver must convert the parameter data to the correct data type and re-execute the statement.
Note:
When you create a data source in the Administration Console, the Administration Console sets the BatchPeformanceWorkaround connection property to true by default.For data sources used as a JMS JDBC store that use the Oracle Type 4 JDBC driver for DB2, the BatchPerformanceWorkaround property must be set to true.
The DB2 driver supports returning parameter metadata as described in this section.
The DB2 driver supports returning parameter metadata for all types of SQL statements with the following DB2 databases:
DB2 v8.x and higher for Linux/UNIX/Windows
DB2 for z/OS
DB2 V5R2 and higher for iSeries
For DB2 v7x for Linux/UNIX/Windows and DB2 V5R1 for iSeries, the DB2 driver supports returning parameter metadata for the following forms of Insert and Update statements:
INSERT INTO foo VALUES (?, ?, ?)
INSERT INTO foo (col1, col2, col3) VALUES (?, ?, ?)
UPDATE foo SET col1=?, col2=?, col3=? WHERE col1 operator ? [{AND | OR} col2 operator ?]
where operator is any of the following SQL operators: =, <, >, <=, >=, and <>.
The DB2 driver supports returning parameter metadata for all types of SQL statements with the following DB2 databases:
DB2 v8.x and higher for Linux/UNIX/Windows
DB2 for z/OS
DB2 V5R2 and higher for iSeries
For DB2 v7x for Linux/UNIX/Windows and DB2 V5R1 for iSeries, the DB2 driver supports returning parameter metadata for Select statements that contain parameters in ANSI SQL 92 entry-level predicates, for example, such as COMPARISON, BETWEEN, IN, LIKE, and EXISTS predicate constructs. Refer to the ANSI SQL reference for detailed syntax.
Parameter metadata can be returned for a Select statement if one of the following conditions is true:
The statement contains a predicate value expression that can be targeted against the source tables in the associated FROM clause. For example:
SELECT * FROM foo WHERE bar > ?
In this case, the value expression "bar" can be targeted against the table "foo" to determine the appropriate metadata for the parameter.
The statement contains a predicate value expression part that is a nested query. The nested query's metadata must describe a single column. For example:
SELECT * FROM foo WHERE (SELECT x FROM y WHERE z = 1) < ?
The following Select statements show further examples for which parameter metadata can be returned:
SELECT col1, col2 FROM foo WHERE col1 = ? and col2 > ? SELECT ... WHERE colname = (SELECT col2 FROM t2 WHERE col3 = ?) SELECT ... WHERE colname LIKE ? SELECT ... WHERE colname BETWEEN ? and ? SELECT ... WHERE colname IN (?, ?, ?) SELECT ... WHERE EXISTS(SELECT ... FROM T2 WHERE col1 < ?)
ANSI SQL 92 entry-level predicates in a WHERE clause containing GROUP BY, HAVING, or ORDER BY statements are supported. For example:
SELECT * FROM t1 WHERE col = ? ORDER BY 1
Joins are supported. For example:
SELECT * FROM t1,t2 WHERE t1.col1 = ?
Fully qualified names and aliases are supported. For example:
SELECT a, b, c, d FROM T1 AS A, T2 AS B WHERE A.a = ? and B.b = ?"
If your application requires table name information, the DB2 driver can return table name information in ResultSet metadata for Select statements. By setting the ResultSetMetaDataOptions property to 1, the DB2 driver performs additional processing to determine the correct table name for each column in the result set when the ResultSetMetaData.getTableName() method is called. Otherwise, the getTableName() method may return an empty string for each column in the result set.
The table name information that is returned by the DB2 driver depends on whether the column in a result set maps to a column in a table in the database. For each column in a result set that maps to a column in a table in the database, the DB2 driver returns the table name associated with that column. For columns in a result set that do not map to a column in a table (for example, aggregates and literals), the DB2 driver returns an empty string.
The Select statements for which ResultSet metadata is returned may contain aliases, joins, and fully qualified names. The following queries are examples of Select statements for which the ResultSetMetaData.getTableName() method returns the correct table name for columns in the Select list:
SELECT id, name FROM Employee SELECT E.id, E.name FROM Employee E SELECT E.id, E.name AS EmployeeName FROM Employee E SELECT E.id, E.name, I.location, I.phone FROM Employee E, EmployeeInfo I WHERE E.id = I.id SELECT id, name, location, phone FROM Employee, EmployeeInfo WHERE id = empId SELECT Employee.id, Employee.name, EmployeeInfo.location, EmployeeInfo.phone FROM Employee, EmployeeInfo WHERE Employee.id = EmployeeInfo.id
The table name returned by the driver for generated columns is an empty string. The following query is an example of a Select statement that returns a result set that contains a generated column (the column named "upper").
SELECT E.id, E.name as EmployeeName, {fn UCASE(E.name)}
AS upper FROM Employee E
The DB2 driver also can return schema name and catalog name information when the ResultSetMetaData.getSchemaName() and ResultSetMetaData.getCatalogName() methods are called if the driver can determine that information. For example, for the following statement, the DB2 driver returns "test" for the catalog name, "test1" for the schema name, and "foo" for the table name:
SELECT * FROM test.test1.foo
The additional processing required to return table name, schema name, and catalog name information is only performed if the ResultSetMetaData.getTableName(), ResultSetMetaData.getSchemaName(), or ResultSetMetaData.getCatalogName() methods are called.
The DB2 driver supports any JSR 114 implementation of the RowSet interface, including:
CachedRowSets
FilteredRowSets
WebRowSets
JoinRowSets
JDBCRowSets
J2SE 1.4 or higher is required to use rowsets with the driver.
See http://www.jcp.org/en/jsr/detail?id=114 for more information about JSR 114.
The DB2 driver supports retrieving the values of auto-generated keys. An auto-generated key returned by the DB2 driver is the value of an auto-increment column.
An application can return values of auto-generated keys when it executes an Insert statement. How you return these values depends on whether you are using an Insert statement that contains parameters:
When using an Insert statement that does not contain any parameters, the DB2 driver supports the following form of the Statement.execute() and Statement.executeUpdate() methods to instruct the driver to return values of auto-generated keys:
Statement.execute(String sql, int autoGeneratedKeys)
Statement.execute(String sql, int[] columnIndexes)
Statement.execute(String sql, String[] columnNames)
Statement.executeUpdate(String sql, int autoGeneratedKeys)
Statement.executeUpdate(String sql, int[] columnIndexes)
Statement.executeUpdate(String sql, String[] columnNames)
When using an Insert statement that contains parameters, the DB2 driver supports the following form of the Connection.prepareStatement method to inform the driver to return the values of auto-generated keys:
Connection.prepareStatement(String sql, int autoGeneratedKeys)
Connection.prepareStatement(String sql, int[] columnIndexes)
Connection.prepareStatement(String sql, String[] columnNames)
An application can retrieve values of auto-generated keys using the Statement.getGeneratedKeys() method. This method returns a ResultSet object with a column for each auto-generated key.
The new Database connection property can be used as a synonym of the DatabaseName connection property.
If both the Database and DatabaseName connection properties are specified in a connection URL, the last of either property positioned in the connection URL is used. For example, if your application specifies the following connection URL, the value of the Database connection property would be used instead of the value of the DatabaseName connection property.
jdbc:weblogic:db2://server1:50000;DatabaseName=jdbc;Database=acct; User=test;Password=secret
The LocationName connection property is only supported when connecting to DB2 for z/OS or iSeries to specify the name of the DB2 location. Now, your application can use the DatabaseName connection property when you are connecting to DB2 for Linux/UNIX/Windows, z/OS, or iSeries.
When connecting to DB2 for Linux/UNIX/Windows, the DatabaseName connection property specifies the name of the database. When connecting to DB2 for z/OS or iSeries, the DatabaseName connection property specifies the name of the DB2 location.
The DB2 driver now supports:
New data types for storing graphic data on all DB2 database versions
New data types for DB2 v9.1 for z/OS, including the XML data type, which previously was supported only for DB2 V9.1 for Linux/UNIX/Windows
Table 3-7 and Table 3-8 list these data types and describe how they are mapped to JDBC data types.
Table 3-7 DB2 Graphic Data Types
| DB2 Data Type | JDBC Data Type |
|---|---|
|
Graphic |
CHAR |
|
Long Vargraphic |
LONGVARCHAR |
|
Vargraphic |
VARCHAR |
Table 3-8 New DB2 Data Types Supported for DB2 v9.1 for z/OS
| DB2 Data Type | JDBC Data Type |
|---|---|
|
Bigint |
BIGINT |
|
Binary |
BINARY |
|
Decfloat |
DECIMAL |
|
Varbinary |
VARBINARY |
|
XML |
CLOB |
See Appendix B, "GetTypeInfo" for a description of the data types returned by the getTypeInfo() method.
For more information about using the XML data type, see Returning and Inserting/Updating XML Data.
For information about other data types supported by the DB2 driver, see Data Types.
SQL Procedures now are supported for DB2 v9.1 for z/OS.
The DB2 driver now supports IPv6 for DB2 v9.1 for z/OS.
For more information about IPv6, see Using IP Addresses.
The driver supports DataDirect Bulk Load, a feature that allows your application to send large numbers of rows of data to the database in a continuous stream instead of in numerous smaller database protocol packets. Similar to batch operations, performance improves because far fewer network round trips are required. Bulk load bypasses the data parsing usually done by the database, providing an additional performance gain over batch operations.