oracle.javatools.db.execute

Class QueryWrapper

java.lang.Object

oracle.javatools.db.execute.StatementWrapper

oracle.javatools.db.execute.QueryWrapper

Direct Known Subclasses:

PlSqlWrapper

public class QueryWrapper
extends StatementWrapper

Execution wrapper for querying the database and processing ResultSets (rather than just executing statements). On top of what StatementWrapper provides, it provides:

1. Automatic parameter support, use ? and the parameters will be substituted using a PreparedStatement, use {0}, {1} etc and java.text.MessageFormat will be used instead.
2. DBObjects as parameters - convert them to strings properly
3. Auto-closing of the java.sql.ResultSet and java.sql.Statement after execution.

Example Usage:

 final Database db = ...;
 final Schema schema = ...;
 final String query = ...;
 final QueryWrapper wrap = new QueryWrapper( db, query, new Object[]{ schema });
 final QueryWrapper.QueryRunnable r =
   new QueryWrapper.QueryRunnable()
   {
     public void processResultSet( ResultSet rs )
     throws SQLException, DBException
     {
       while( rs.next() )
       {
         // process the result set as appropriate
       }
     }
   };

 try
 {
   wrap.executeQuery( r );
 }
 catch( DBException dbe )
 {
   // process exception
 }
 

Since:

11.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	QueryWrapper.QueryRunnable A QueryRunnable implementation is passed to the QueryWrapper on execute of the query to process the resulting ResultSet.

Nested classes/interfaces inherited from class oracle.javatools.db.execute.StatementWrapper

StatementWrapper.ExecutionProxy, StatementWrapper.ExecutionRunnable<T>, StatementWrapper.Listener

Constructor Summary

Constructors

Constructor and Description
QueryWrapper(Database db, java.lang.String query) Creates a wrapper for a query with no parameters.
QueryWrapper(Database db, java.lang.String query, java.util.List params) Creates a wrapper for the given query text.
QueryWrapper(Database db, java.lang.String query, java.lang.Object... params) Creates a wrapper for the given query text.
QueryWrapper(java.lang.String name, java.sql.Connection conn, java.lang.String query, java.lang.Object... params) Only use in the absence of a Database (e.g.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the statement and result set if we got that far.
protected java.sql.Statement	createStatment() Creates the Statement object to use.
boolean	execute() Executes the statment against the database.
void	executeQuery(int fetchSize, QueryWrapper.QueryRunnable run) Execute the query against the builder's connection using the appropriate parameter substitutions.
void	executeQuery(QueryWrapper.QueryRunnable run) Execute the query against the builder's connection using the appropriate parameter substitutions.
java.lang.String	executeSingleCellQuery() Convenience method that executes the query and expects a single row with a single column.
java.lang.String	getDatabaseName()
protected java.util.List<java.lang.Object>	getParameters() Returns the parameters to substitute on the statement.
protected java.lang.String	getQuery() Returns the query string.
java.lang.String	getStatementTextForLog() For logging and exception handling.
void	setContextObject(DBObject obj) Sets a context DBObject that the statement is being executed for.
void	setDatabaseName(java.lang.String dbName)
static QueryWrapper	union(QueryWrapper... wrappers) Unions together the queries in the given wrapper and bundles up all the parameters (if any) to be used with the various queries.

Methods inherited from class oracle.javatools.db.execute.StatementWrapper

addListener, cancel, cancelExecution, createDBSQLException, createDBSQLException, doExecute, executeImpl, getConnection, getConnectionName, getDatabase, getExecutionProxy, getIdentifier, getLogger, getStatement, getStatementStrings, hasCancelled, isCancelled, isExecutionProxyThread, isIgnoreErrors, queryFinished, queryStarted, removeListener, setBypassExecutionProxy, setDatabase, setExecuting, setExecutionProxy, setIdentifier, setIgnoreErrors, setStatement, sqlTrace, throwCancelledException, throwDBException, throwDBException, throwDBException

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QueryWrapper

public QueryWrapper(Database db,
                    java.lang.String query)

Creates a wrapper for a query with no parameters.

See Also:

#QueryWrapper(java.sql.Connection, java.lang.String, java.lang.Object...)

QueryWrapper

public QueryWrapper(Database db,
                    java.lang.String query,
                    java.lang.Object... params)

Creates a wrapper for the given query text. The params are set on the statement as strings. If any of the params is a DBObject its correct string representation is used.

QueryWrapper

public QueryWrapper(java.lang.String name,
                    java.sql.Connection conn,
                    java.lang.String query,
                    java.lang.Object... params)

Only use in the absence of a Database (e.g. in unit tests).

QueryWrapper

public QueryWrapper(Database db,
                    java.lang.String query,
                    java.util.List params)

Creates a wrapper for the given query text. The params are set on the statement as strings. If any of the params is a DBObject its correct string representation is used.

Method Detail

setContextObject

public void setContextObject(DBObject obj)

Sets a context DBObject that the statement is being executed for. This will be used in any thrown DBExceptions.

If the object has a DBObjectID with a databaseName set this will also set the databaseName on this wrapper.

Overrides:

setContextObject in class StatementWrapper

Parameters:

obj - the context object for this wrapper

setDatabaseName

public final void setDatabaseName(java.lang.String dbName)

getDatabaseName

public final java.lang.String getDatabaseName()

createStatment

protected java.sql.Statement createStatment()
                                     throws java.sql.SQLException

Description copied from class: StatementWrapper

Creates the Statement object to use. By default this creates a simple Statement, subclasses can override to create a Prepared or Callable statement.

Overrides:

createStatment in class StatementWrapper

Throws:

java.sql.SQLException

getStatementTextForLog

public java.lang.String getStatementTextForLog()

Description copied from class: StatementWrapper

For logging and exception handling. Returns the statement text that will be executed. This may not be executable SQL, it is only intended for logging.

Overrides:

getStatementTextForLog in class StatementWrapper

getQuery

protected java.lang.String getQuery()

Returns the query string. If using message format for the parameters this will substitute the parameters into the query.

See Also:

setMessageFormat()

getParameters

protected java.util.List<java.lang.Object> getParameters()

Returns the parameters to substitute on the statement. If using message format for the parameters this will return an empty list.

See Also:

getQuery()

execute

public final boolean execute()
                      throws DBException

Description copied from class: StatementWrapper

Executes the statment against the database. Returns true if the execution succeeded (i.e. java.sql.Statement.execute() returned true). If multiple statements are included, true is returned if any succeed. If an error occurs (SQLException) execution halts at that statement.

Overrides:

execute in class StatementWrapper

Throws:

DBException

See Also:

Statement.execute(java.lang.String)

executeSingleCellQuery

public java.lang.String executeSingleCellQuery()
                                        throws DBException

Convenience method that executes the query and expects a single row with a single column. It returns the value of that single data cell as a String.

Throws:

DBException

executeQuery

public void executeQuery(int fetchSize,
                         QueryWrapper.QueryRunnable run)
                  throws DBException

Execute the query against the builder's connection using the appropriate parameter substitutions.

Parameters:

fetchSize - Gives the JDBC driver a hint as to the number of rows that should be fetched from the database when more rows are needed. If the value specified is zero, then the hint is ignored.

Throws:

DBException

executeQuery

public void executeQuery(QueryWrapper.QueryRunnable run)
                  throws DBException

Execute the query against the builder's connection using the appropriate parameter substitutions.

Throws:

DBException

close

public void close()

Closes the statement and result set if we got that far. Call in a finally{ ... } block.

Overrides:

close in class StatementWrapper

union

public static QueryWrapper union(QueryWrapper... wrappers)

Unions together the queries in the given wrapper and bundles up all the parameters (if any) to be used with the various queries.

No checking is done on the number of columns - the database will complain if they don't match.