WebLogic Type 4 JDBC Drivers
The following sections describe how to configure and use the BEA WebLogic Type 4 JDBC SQL Server driver:
Note: The BEA WebLogic Type 4 JDBC MS SQL Server driver (the subject of this chapter) replaces the WebLogic jDriver for Microsoft SQL Server, which is deprecated. The new driver offers JDBC 3.0 compliance, support for some JDBC 2.0 extensions, and better performance. BEA recommends that you use the new BEA WebLogic Type 4 JDBC MS SQL Server driver in place of the WebLogic jDriver for Microsoft SQL Server.
The BEA WebLogic Type 4 JDBC MS SQL Server driver (the "SQL Server driver") supports the following database management system versions:
To use JDBC distributed transactions through JTA, you must install stored procedures for SQL Server. See Installing Stored Procedures for JTA for details.
The driver classes for the BEA WebLogic Type 4 JDBC MS SQL Server driver are:
XA: weblogic.jdbcx.sqlserver.SQLServerDataSource
Non-XA: weblogic.jdbc.sqlserver.SQLServerDriver
To connect to a Microsoft SQL Server database, use the following URL format:
jdbc:bea:sqlserver://
dbserver
:
port
Microsoft SQL Server supports multiple instances of a SQL Server database running concurrently on the same server. An instance is identified by an instance name.
To connect to a named instance using a connection URL, use the following URL format:
jdbc:bea:sqlserver://server_name\\instance_name
Note: The first back slash character (\
) in \\
instance_name
is an escape character.
server_name
is the IP address or hostname of the server.
instance_name
is the name of the instance to which you want to connect on the server.
For example, the following connection URL connects to an instance named instance1 on server1:
jdbc:bea:sqlserver://server1\\instance1;User=test;Pasword=secret
Table 5-1 lists the JDBC connection properties supported by the SQL Server driver, and describes each property. You can use these connection properties in a JDBC data source configuration in your WebLogic Server domain. To specify a property, use the following form in the JDBC data source configuration:
property=value
Note: All connection string property names are case-insensitive. For example, Password is the same as password.
{true | false}. Determines how the driver reports results generated by database triggers (procedures that are stored in the database and executed, or fired, when a table is modified). If set to true, the driver returns all results, including results generated by triggers. Multiple trigger results are returned one at a time. Use the Statement.getMoreResults method to retrieve individual trigger results. Warnings and errors are reported in the results as they are encountered. If set to false, the driver does not report trigger results if the statement is a single Insert, Update, or Delete statement. In this case, the only result that is returned is the update count generated by the statement that was executed (if errors do not occur). Although trigger results are ignored, any errors generated by the trigger are reported. Any warnings generated by the trigger are enqueued. If errors are reported, the update count is not reported. |
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Specifies the code page the driver uses when converting character data. The specified code page overrides the default database code page. All character data retrieved from or written to the database is converted using the specified code page. The value must be a string containing the name of a valid code page supported by your Java Virtual Machine, for example, CodePageOverride=CP950. If a value is set for the CodePageOverride property and the SendStringParametersAsUnicode property is set to true, the driver ignores the SendStringParametersAsUnicode property and generates a warning. The driver always sends parameters using the code page specified by CodePageOverride if this property is specified. |
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The number of times the driver retries connections to a database server until a successful connection is established. Valid values are 0 and any positive integer. If set to 0, the driver does not retry a connection to the list of database servers if a connection is not established on the driver's first pass through the list. |
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The number of seconds the driver waits before retrying connection attempts when ConnectionRetryCount is set to a positive integer. |
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The process ID of the application connecting to Microsoft SQL Server. The value of this property appears in the hostprocess column of the master.dbo.sysprocesses table and may be useful for database administration purposes. |
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{-1 | 0 | x}. Determines the amount of memory used by the driver to cache insensitive result set data. It must have one of the following values: If set to -1, the driver caches all insensitive result set data in memory. If the size of the result set exceeds available memory, an OutOfMemoryException is generated. Because the need to write result set data to disk is eliminated, the driver processes the data more efficiently. If set to 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 set to x, where x is a positive integer, the driver caches all insensitive result set data in memory, using this value to set the size (in KB) of the memory buffer for caching 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. |
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The Media Access Control (MAC) address of the network interface card of the application connecting to Microsoft SQL Server. The value of this property appears in the net_address column of the master.dbo.sysprocesses table and may be useful for database administration purposes. |
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A case-insensitive password used to connect to your Microsoft SQL Server database. |
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The TCP port of the primary database server that is listening for connections to the Microsoft SQL Server database. |
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The name of the application connecting to Microsoft SQL Server. The value of this property appears in the program_name column of the master.dbo.sysprocesses table and may be useful for database administration purposes. |
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{direct | cursor}. A hint to the driver that determines whether the driver requests a database cursor for Select statements. Performance and behavior of the driver are affected by this property, which is defined as a hint because the driver may not always be able to satisfy the requested method.
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{true | false}. Determines whether string parameters are sent to the Microsoft SQL Server database in Unicode or in the default character encoding of the database. If set to true, string parameters are sent to Microsoft SQL Server in Unicode. If set to false, string parameters are sent in the default encoding, which can improve performance because the server does not need to convert Unicode characters to the default encoding. You should, however, use default encoding only if the parameter string data you specify is the same as the default encoding of the database. If a value is specified for the CodePageOverride property and this property is set to true, this property is ignored and a warning is generated. |
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Specifies either the IP address or the server name (if your network supports named servers) of the primary database server. For example, 122.23.15.12 or SQLServerServer. To connect to a named instance, specify |
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The case-insensitive user name used to connect to your Microsoft SQL Server database. |
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{true | false}. Determines whether the driver uses server-side cursors when an updatable result set is requested. If set to true, server-side updatable cursors are created when an updatable result set is requested. If set to false, the default updatable result set functionality is used. See Server-Side Updatable Cursors for more information about using server-side updatable cursors. |
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The workstation ID, which typically is the network name of the computer on which the application resides. If specified, this value is stored in the hostname column of the master.dbo.sysprocesses table and can be returned by sp_who and the Transact-SQL HOST_NAME function. The value can be useful for database administration purposes. |
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The transaction group ID that identifies any transactions initiated by the connection. This ID can be used for distributed transaction cleanup purposes. |
Table 5-2 lists the data types supported by the SQL Server driver in SQL Server 7 and SQL Server 2000 and how they are mapped to the JDBC data types.
Table 5-3 lists additional data types supported by SQL Server 2000 only.
See GetTypeInfo for more information about data types.
See SQL Escape Sequences for JDBC, for information about the SQL escape sequences supported by the SQL Server driver.
The SQL Server driver supports the Read Committed, Read Uncommitted, Repeatable Read, and Serializable isolation levels. The default is Read Committed.
The SQL Server driver supports scroll-sensitive result sets, scroll-insensitive result sets, and updatable result sets.
Note: When the SQL Server driver cannot support the requested result set type or concurrency, it automatically downgrades the cursor and generates one or more SQLWarnings with detailed information.
In most cases, using server-side updatable cursors is faster, but server-side updatable cursors cannot be used with insensitive result sets or with sensitive result sets that do not have a primary key. By default, the MS SQL Server driver allows insensitive result sets and sensitive result sets that do not contain a primary key to be updatable. To use server-side cursors when an updatable result set is requested, you set the UseServerSideUpdatableCursors
property.
When the UseServerSideUpdatableCursors
property is set to true and a scroll-insensitive updatable result set is requested, the driver downgrades the request to a scroll-insensitive read-only result set. Similarly, when a scroll-sensitive updatable result set is requested and the table does not contain a primary key, the driver downgrades the request to a scroll-sensitive read-only result set. In either case, a warning is generated.
When server-side updatable cursors are used with sensitive result sets that contain a primary key, any changes you make to the result set are visible. Using the default behavior of the driver, those changes would not be visible.
To use JDBC distributed transactions through JTA, your system administrator should use the following procedure to install Microsoft SQL Server JDBC XA procedures. This procedure must be repeated for each MS SQL Server installation that will be involved in a distributed transaction.
sqljdbc.dll
and instjdbc.sql
files from the WL_HOME
\server\lib
directory to the SQL_Server_Root
/bin
directory of the MS SQL Server database server, where WL_HOME
is the directory in which WebLogic server is installed, typically c:\bea\weblogic81
.Note: If you are installing stored procedures on a database server with multiple Microsoft SQL Server instances, each running SQL Server instance must be able to locate the sqljdbc.dll
file. Therefore the sqljdbc.dll
file needs to be anywhere on the global PATH or on the application-specific path. For the application-specific path, place the sqljdbc.dll
file into the <drive>:\Program Files\Microsoft SQL Server\MSSQL$<Instance 1 Name>\Binn
directory for each instance.
instjdbc.sql
script. The system administrator should back up the master database before running instjdbc.sql
.At a command prompt, use the following syntax to run instjdbc.sql
:
ISQL -Usa -Psa_password -Sserver_name -ilocation\instjdbc.sql
sa_password is the password of the system administrator.
server_name is the name of the server on which SQL Server resides.
location is the full path to instjdbc.sql
. (You copied this script to the SQL_Server_Root
/bin
directory in step 1.)
The instjdbc.sql
script generates many messages. In general, these messages can be ignored; however, the system administrator should scan the output for any messages that may indicate an execution error. The last message should indicate that instjdbc.sql
ran successfully. The script fails when there is insufficient space available in the master database to store the JDBC XA procedures or to log changes to existing procedures.
Although Microsoft SQL Server does not define a Blob or Clob data type, the SQL Server driver allows you to retrieve and update long data, specifically LONGVARBINARY and LONGVARCHAR data, using JDBC methods designed for Blobs and Clobs. When using these methods to update long data as Blobs or Clobs, the updates are made to the local copy of the data contained in the Blob or Clob object.
Retrieving and updating long data using JDBC methods designed for Blobs and Clobs provides some of the same advantages as retrieving and updating Blobs and Clobs. For example, using Blobs and Clobs:
To provide these advantages of Blobs and Clobs, data must be cached. Because data is cached, you will incur a performance penalty, particularly if the data is read once sequentially. This performance penalty can be severe if the size of the long data is larger than available memory.
The SQL Server driver implementation for batch Inserts and Updates is JDBC 3.0 compliant. When the SQL Server driver detects an error in a statement or parameter set in a batch Insert or Update, it generates a BatchUpdateException and continues to execute the remaining statements or parameter sets in the batch. The array of update counts contained in the BatchUpdateException contain one entry for each statement or parameter set. Any entries for statements or parameter sets that failed contain the value Statement.EXECUTE_FAILED.
The SQL Server driver supports returning parameter metadata for the following forms of SQL:
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 SQL Server driver supports retrieving the values of auto-generated keys. An auto-generated key returned by the SQL Server driver is the value of an identity column.
How you return those values depends on whether you are using an Insert statement that contains parameters:
Statement.execute
and Statement.executeUpdate
methods to inform the driver to return the values of auto-generated keys: Statement.execute (String sql, int autoGeneratedKeys)
Statement.executeUpdate (String sql, int autoGeneratedKeys)
Connection.prepareStatement
method to inform the driver to return the values of auto-generated keys:The application fetches the values of generated keys from the driver using the Statement.getGeneratedKeys ()
method.