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Statement.javaAPI DocJava SE 6 API43128Tue Jun 10 00:25:50 BST 2008java.sql

Statement

public interface Statement implements Wrapper

The object used for executing a static SQL statement and returning the results it produces.

By default, only one ResultSet object per Statement object can be open at the same time. Therefore, if the reading of one ResultSet object is interleaved with the reading of another, each must have been generated by different Statement objects. All execution methods in the Statement interface implicitly close a statment's current ResultSet object if an open one exists.

see
Connection#createStatement
see
ResultSet

Fields Summary
int
CLOSE_CURRENT_RESULT
The constant indicating that the current ResultSet object should be closed when calling getMoreResults.
int
KEEP_CURRENT_RESULT
The constant indicating that the current ResultSet object should not be closed when calling getMoreResults.
int
CLOSE_ALL_RESULTS
The constant indicating that all ResultSet objects that have previously been kept open should be closed when calling getMoreResults.
int
SUCCESS_NO_INFO
The constant indicating that a batch statement executed successfully but that no count of the number of rows it affected is available.
int
EXECUTE_FAILED
The constant indicating that an error occured while executing a batch statement.
int
RETURN_GENERATED_KEYS
The constant indicating that generated keys should be made available for retrieval.
int
NO_GENERATED_KEYS
The constant indicating that generated keys should not be made available for retrieval.
Constructors Summary
Methods Summary
public voidaddBatch(java.lang.String sql)
Adds the given SQL command to the current list of commmands for this Statement object. The commands in this list can be executed as a batch by calling the method executeBatch.

param
sql typically this is a SQL INSERT or UPDATE statement
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the driver does not support batch updates
see
#executeBatch
see
DatabaseMetaData#supportsBatchUpdates
since
1.2

public voidcancel()
Cancels this Statement object if both the DBMS and driver support aborting an SQL statement. This method can be used by one thread to cancel a statement that is being executed by another thread.

exception
SQLException if a database access error occurs or this method is called on a closed Statement
exception
SQLFeatureNotSupportedException if the JDBC driver does not support this method

public voidclearBatch()
Empties this Statement object's current list of SQL commands.

exception
SQLException if a database access error occurs, this method is called on a closed Statement or the driver does not support batch updates
see
#addBatch
see
DatabaseMetaData#supportsBatchUpdates
since
1.2

public voidclearWarnings()
Clears all the warnings reported on this Statement object. After a call to this method, the method getWarnings will return null until a new warning is reported for this Statement object.

exception
SQLException if a database access error occurs or this method is called on a closed Statement

public voidclose()
Releases this Statement object's database and JDBC resources immediately instead of waiting for this to happen when it is automatically closed. It is generally good practice to release resources as soon as you are finished with them to avoid tying up database resources.

Calling the method close on a Statement object that is already closed has no effect.

Note:When a Statement object is closed, its current ResultSet object, if one exists, is also closed.

exception
SQLException if a database access error occurs

public booleanexecute(java.lang.String sql)
Executes the given SQL statement, which may return multiple results. In some (uncommon) situations, a single SQL statement may return multiple result sets and/or update counts. Normally you can ignore this unless you are (1) executing a stored procedure that you know may return multiple results or (2) you are dynamically executing an unknown SQL string.

The execute method executes an SQL statement and indicates the form of the first result. You must then use the methods getResultSet or getUpdateCount to retrieve the result, and getMoreResults to move to any subsequent result(s).

param
sql any SQL statement
return
true if the first result is a ResultSet object; false if it is an update count or there are no results
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#getResultSet
see
#getUpdateCount
see
#getMoreResults

public booleanexecute(java.lang.String sql, int autoGeneratedKeys)
Executes the given SQL statement, which may return multiple results, and signals the driver that any auto-generated keys should be made available for retrieval. The driver will ignore this signal if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys (the list of such statements is vendor-specific).

In some (uncommon) situations, a single SQL statement may return multiple result sets and/or update counts. Normally you can ignore this unless you are (1) executing a stored procedure that you know may return multiple results or (2) you are dynamically executing an unknown SQL string.

The execute method executes an SQL statement and indicates the form of the first result. You must then use the methods getResultSet or getUpdateCount to retrieve the result, and getMoreResults to move to any subsequent result(s).

param
sql any SQL statement
param
autoGeneratedKeys a constant indicating whether auto-generated keys should be made available for retrieval using the method getGeneratedKeys; one of the following constants: Statement.RETURN_GENERATED_KEYS or Statement.NO_GENERATED_KEYS
return
true if the first result is a ResultSet object; false if it is an update count or there are no results
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the second parameter supplied to this method is not Statement.RETURN_GENERATED_KEYS or Statement.NO_GENERATED_KEYS.
exception
SQLFeatureNotSupportedException if the JDBC driver does not support this method with a constant of Statement.RETURN_GENERATED_KEYS
see
#getResultSet
see
#getUpdateCount
see
#getMoreResults
see
#getGeneratedKeys
since
1.4

public booleanexecute(java.lang.String sql, int[] columnIndexes)
Executes the given SQL statement, which may return multiple results, and signals the driver that the auto-generated keys indicated in the given array should be made available for retrieval. This array contains the indexes of the columns in the target table that contain the auto-generated keys that should be made available. The driver will ignore the array if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys (the list of such statements is vendor-specific).

Under some (uncommon) situations, a single SQL statement may return multiple result sets and/or update counts. Normally you can ignore this unless you are (1) executing a stored procedure that you know may return multiple results or (2) you are dynamically executing an unknown SQL string.

The execute method executes an SQL statement and indicates the form of the first result. You must then use the methods getResultSet or getUpdateCount to retrieve the result, and getMoreResults to move to any subsequent result(s).

param
sql any SQL statement
param
columnIndexes an array of the indexes of the columns in the inserted row that should be made available for retrieval by a call to the method getGeneratedKeys
return
true if the first result is a ResultSet object; false if it is an update count or there are no results
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the elements in the int array passed to this method are not valid column indexes
throws
SQLFeatureNotSupportedException if the JDBC driver does not support this method
see
#getResultSet
see
#getUpdateCount
see
#getMoreResults
since
1.4

public booleanexecute(java.lang.String sql, java.lang.String[] columnNames)
Executes the given SQL statement, which may return multiple results, and signals the driver that the auto-generated keys indicated in the given array should be made available for retrieval. This array contains the names of the columns in the target table that contain the auto-generated keys that should be made available. The driver will ignore the array if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys (the list of such statements is vendor-specific).

In some (uncommon) situations, a single SQL statement may return multiple result sets and/or update counts. Normally you can ignore this unless you are (1) executing a stored procedure that you know may return multiple results or (2) you are dynamically executing an unknown SQL string.

The execute method executes an SQL statement and indicates the form of the first result. You must then use the methods getResultSet or getUpdateCount to retrieve the result, and getMoreResults to move to any subsequent result(s).

param
sql any SQL statement
param
columnNames an array of the names of the columns in the inserted row that should be made available for retrieval by a call to the method getGeneratedKeys
return
true if the next result is a ResultSet object; false if it is an update count or there are no more results
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the elements of the String array passed to this method are not valid column names
throws
SQLFeatureNotSupportedException if the JDBC driver does not support this method
see
#getResultSet
see
#getUpdateCount
see
#getMoreResults
see
#getGeneratedKeys
since
1.4

public int[]executeBatch()
Submits a batch of commands to the database for execution and if all commands execute successfully, returns an array of update counts. The int elements of the array that is returned are ordered to correspond to the commands in the batch, which are ordered according to the order in which they were added to the batch. The elements in the array returned by the method executeBatch may be one of the following:
  1. A number greater than or equal to zero -- indicates that the command was processed successfully and is an update count giving the number of rows in the database that were affected by the command's execution
  2. A value of SUCCESS_NO_INFO -- indicates that the command was processed successfully but that the number of rows affected is unknown

    If one of the commands in a batch update fails to execute properly, this method throws a BatchUpdateException, and a JDBC driver may or may not continue to process the remaining commands in the batch. However, the driver's behavior must be consistent with a particular DBMS, either always continuing to process commands or never continuing to process commands. If the driver continues processing after a failure, the array returned by the method BatchUpdateException.getUpdateCounts will contain as many elements as there are commands in the batch, and at least one of the elements will be the following:

  3. A value of EXECUTE_FAILED -- indicates that the command failed to execute successfully and occurs only if a driver continues to process commands after a command fails

The possible implementations and return values have been modified in the Java 2 SDK, Standard Edition, version 1.3 to accommodate the option of continuing to proccess commands in a batch update after a BatchUpdateException obejct has been thrown.

return
an array of update counts containing one element for each command in the batch. The elements of the array are ordered according to the order in which commands were added to the batch.
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the driver does not support batch statements. Throws {@link BatchUpdateException} (a subclass of SQLException) if one of the commands sent to the database fails to execute properly or attempts to return a result set.
see
#addBatch
see
DatabaseMetaData#supportsBatchUpdates
since
1.3

public java.sql.ResultSetexecuteQuery(java.lang.String sql)
Executes the given SQL statement, which returns a single ResultSet object.

param
sql an SQL statement to be sent to the database, typically a static SQL SELECT statement
return
a ResultSet object that contains the data produced by the given query; never null
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the given SQL statement produces anything other than a single ResultSet object

public intexecuteUpdate(java.lang.String sql)
Executes the given SQL statement, which may be an INSERT, UPDATE, or DELETE statement or an SQL statement that returns nothing, such as an SQL DDL statement.

param
sql an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE; or an SQL statement that returns nothing, such as a DDL statement.
return
either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0 for SQL statements that return nothing
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the given SQL statement produces a ResultSet object

public intexecuteUpdate(java.lang.String sql, int autoGeneratedKeys)
Executes the given SQL statement and signals the driver with the given flag about whether the auto-generated keys produced by this Statement object should be made available for retrieval. The driver will ignore the flag if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys (the list of such statements is vendor-specific).

param
sql an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE; or an SQL statement that returns nothing, such as a DDL statement.
param
autoGeneratedKeys a flag indicating whether auto-generated keys should be made available for retrieval; one of the following constants: Statement.RETURN_GENERATED_KEYS Statement.NO_GENERATED_KEYS
return
either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0 for SQL statements that return nothing
exception
SQLException if a database access error occurs, this method is called on a closed Statement, the given SQL statement returns a ResultSet object, or the given constant is not one of those allowed
exception
SQLFeatureNotSupportedException if the JDBC driver does not support this method with a constant of Statement.RETURN_GENERATED_KEYS
since
1.4

public intexecuteUpdate(java.lang.String sql, int[] columnIndexes)
Executes the given SQL statement and signals the driver that the auto-generated keys indicated in the given array should be made available for retrieval. This array contains the indexes of the columns in the target table that contain the auto-generated keys that should be made available. The driver will ignore the array if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys (the list of such statements is vendor-specific).

param
sql an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE; or an SQL statement that returns nothing, such as a DDL statement.
param
columnIndexes an array of column indexes indicating the columns that should be returned from the inserted row
return
either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0 for SQL statements that return nothing
exception
SQLException if a database access error occurs, this method is called on a closed Statement, the SQL statement returns a ResultSet object, or the second argument supplied to this method is not an int array whose elements are valid column indexes
throws
SQLFeatureNotSupportedException if the JDBC driver does not support this method
since
1.4

public intexecuteUpdate(java.lang.String sql, java.lang.String[] columnNames)
Executes the given SQL statement and signals the driver that the auto-generated keys indicated in the given array should be made available for retrieval. This array contains the names of the columns in the target table that contain the auto-generated keys that should be made available. The driver will ignore the array if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys (the list of such statements is vendor-specific).

param
sql an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE; or an SQL statement that returns nothing, such as a DDL statement.
param
columnNames an array of the names of the columns that should be returned from the inserted row
return
either the row count for INSERT, UPDATE, or DELETE statements, or 0 for SQL statements that return nothing
exception
SQLException if a database access error occurs, this method is called on a closed Statement, the SQL statement returns a ResultSet object, or the second argument supplied to this method is not a String array whose elements are valid column names
throws
SQLFeatureNotSupportedException if the JDBC driver does not support this method
since
1.4

public java.sql.ConnectiongetConnection()
Retrieves the Connection object that produced this Statement object.

return
the connection that produced this statement
exception
SQLException if a database access error occurs or this method is called on a closed Statement
since
1.2

public intgetFetchDirection()
Retrieves the direction for fetching rows from database tables that is the default for result sets generated from this Statement object. If this Statement object has not set a fetch direction by calling the method setFetchDirection, the return value is implementation-specific.

return
the default fetch direction for result sets generated from this Statement object
exception
SQLException if a database access error occurs or this method is called on a closed Statement
since
1.2
see
#setFetchDirection

public intgetFetchSize()
Retrieves the number of result set rows that is the default fetch size for ResultSet objects generated from this Statement object. If this Statement object has not set a fetch size by calling the method setFetchSize, the return value is implementation-specific.

return
the default fetch size for result sets generated from this Statement object
exception
SQLException if a database access error occurs or this method is called on a closed Statement
since
1.2
see
#setFetchSize

public java.sql.ResultSetgetGeneratedKeys()
Retrieves any auto-generated keys created as a result of executing this Statement object. If this Statement object did not generate any keys, an empty ResultSet object is returned.

Note:If the columns which represent the auto-generated keys were not specified, the JDBC driver implementation will determine the columns which best represent the auto-generated keys.

return
a ResultSet object containing the auto-generated key(s) generated by the execution of this Statement object
exception
SQLException if a database access error occurs or this method is called on a closed Statement
throws
SQLFeatureNotSupportedException if the JDBC driver does not support this method
since
1.4

public intgetMaxFieldSize()
Retrieves the maximum number of bytes that can be returned for character and binary column values in a ResultSet object produced by this Statement object. This limit applies only to BINARY, VARBINARY, LONGVARBINARY, CHAR, VARCHAR, NCHAR, NVARCHAR, LONGNVARCHAR and LONGVARCHAR columns. If the limit is exceeded, the excess data is silently discarded.

return
the current column size limit for columns storing character and binary values; zero means there is no limit
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#setMaxFieldSize

public intgetMaxRows()
Retrieves the maximum number of rows that a ResultSet object produced by this Statement object can contain. If this limit is exceeded, the excess rows are silently dropped.

return
the current maximum number of rows for a ResultSet object produced by this Statement object; zero means there is no limit
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#setMaxRows

public booleangetMoreResults()
Moves to this Statement object's next result, returns true if it is a ResultSet object, and implicitly closes any current ResultSet object(s) obtained with the method getResultSet.

There are no more results when the following is true:

// stmt is a Statement object
((stmt.getMoreResults() == false) && (stmt.getUpdateCount() == -1))

return
true if the next result is a ResultSet object; false if it is an update count or there are no more results
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#execute

public booleangetMoreResults(int current)
Moves to this Statement object's next result, deals with any current ResultSet object(s) according to the instructions specified by the given flag, and returns true if the next result is a ResultSet object.

There are no more results when the following is true:

// stmt is a Statement object
((stmt.getMoreResults(current) == false) && (stmt.getUpdateCount() == -1))

param
current one of the following Statement constants indicating what should happen to current ResultSet objects obtained using the method getResultSet: Statement.CLOSE_CURRENT_RESULT, Statement.KEEP_CURRENT_RESULT, or Statement.CLOSE_ALL_RESULTS
return
true if the next result is a ResultSet object; false if it is an update count or there are no more results
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the argument supplied is not one of the following: Statement.CLOSE_CURRENT_RESULT, Statement.KEEP_CURRENT_RESULT or Statement.CLOSE_ALL_RESULTS
exception
SQLFeatureNotSupportedException if DatabaseMetaData.supportsMultipleOpenResults returns false and either Statement.KEEP_CURRENT_RESULT or Statement.CLOSE_ALL_RESULTS are supplied as the argument.
since
1.4
see
#execute

public intgetQueryTimeout()
Retrieves the number of seconds the driver will wait for a Statement object to execute. If the limit is exceeded, a SQLException is thrown.

return
the current query timeout limit in seconds; zero means there is no limit
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#setQueryTimeout

public java.sql.ResultSetgetResultSet()
Retrieves the current result as a ResultSet object. This method should be called only once per result.

return
the current result as a ResultSet object or null if the result is an update count or there are no more results
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#execute

public intgetResultSetConcurrency()
Retrieves the result set concurrency for ResultSet objects generated by this Statement object.

return
either ResultSet.CONCUR_READ_ONLY or ResultSet.CONCUR_UPDATABLE
exception
SQLException if a database access error occurs or this method is called on a closed Statement
since
1.2

public intgetResultSetHoldability()
Retrieves the result set holdability for ResultSet objects generated by this Statement object.

return
either ResultSet.HOLD_CURSORS_OVER_COMMIT or ResultSet.CLOSE_CURSORS_AT_COMMIT
exception
SQLException if a database access error occurs or this method is called on a closed Statement
since
1.4

public intgetResultSetType()
Retrieves the result set type for ResultSet objects generated by this Statement object.

return
one of ResultSet.TYPE_FORWARD_ONLY, ResultSet.TYPE_SCROLL_INSENSITIVE, or ResultSet.TYPE_SCROLL_SENSITIVE
exception
SQLException if a database access error occurs or this method is called on a closed Statement
since
1.2

public intgetUpdateCount()
Retrieves the current result as an update count; if the result is a ResultSet object or there are no more results, -1 is returned. This method should be called only once per result.

return
the current result as an update count; -1 if the current result is a ResultSet object or there are no more results
exception
SQLException if a database access error occurs or this method is called on a closed Statement
see
#execute

public java.sql.SQLWarninggetWarnings()
Retrieves the first warning reported by calls on this Statement object. Subsequent Statement object warnings will be chained to this SQLWarning object.

The warning chain is automatically cleared each time a statement is (re)executed. This method may not be called on a closed Statement object; doing so will cause an SQLException to be thrown.

Note: If you are processing a ResultSet object, any warnings associated with reads on that ResultSet object will be chained on it rather than on the Statement object that produced it.

return
the first SQLWarning object or null if there are no warnings
exception
SQLException if a database access error occurs or this method is called on a closed Statement

public booleanisClosed()
Retrieves whether this Statement object has been closed. A Statement is closed if the method close has been called on it, or if it is automatically closed.

return
true if this Statement object is closed; false if it is still open
throws
SQLException if a database access error occurs
since
1.6

public booleanisPoolable()
Returns a value indicating whether the Statement is poolable or not.

return
true if the Statement is poolable; false otherwise

throws
SQLException if this method is called on a closed Statement

since
1.6

see
java.sql.Statement#setPoolable(boolean) setPoolable(boolean)

public voidsetCursorName(java.lang.String name)
Sets the SQL cursor name to the given String, which will be used by subsequent Statement object execute methods. This name can then be used in SQL positioned update or delete statements to identify the current row in the ResultSet object generated by this statement. If the database does not support positioned update/delete, this method is a noop. To insure that a cursor has the proper isolation level to support updates, the cursor's SELECT statement should have the form SELECT FOR UPDATE. If FOR UPDATE is not present, positioned updates may fail.

Note: By definition, the execution of positioned updates and deletes must be done by a different Statement object than the one that generated the ResultSet object being used for positioning. Also, cursor names must be unique within a connection.

param
name the new cursor name, which must be unique within a connection
exception
SQLException if a database access error occurs or this method is called on a closed Statement
throws
SQLFeatureNotSupportedException if the JDBC driver does not support this method

public voidsetEscapeProcessing(boolean enable)
Sets escape processing on or off. If escape scanning is on (the default), the driver will do escape substitution before sending the SQL statement to the database. Note: Since prepared statements have usually been parsed prior to making this call, disabling escape processing for PreparedStatements objects will have no effect.

param
enable true to enable escape processing; false to disable it
exception
SQLException if a database access error occurs or this method is called on a closed Statement

public voidsetFetchDirection(int direction)
Gives the driver a hint as to the direction in which rows will be processed in ResultSet objects created using this Statement object. The default value is ResultSet.FETCH_FORWARD.

Note that this method sets the default fetch direction for result sets generated by this Statement object. Each result set has its own methods for getting and setting its own fetch direction.

param
direction the initial direction for processing rows
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the given direction is not one of ResultSet.FETCH_FORWARD, ResultSet.FETCH_REVERSE, or ResultSet.FETCH_UNKNOWN
since
1.2
see
#getFetchDirection

public voidsetFetchSize(int rows)
Gives the JDBC driver a hint as to the number of rows that should be fetched from the database when more rows are needed for ResultSet objects genrated by this Statement. If the value specified is zero, then the hint is ignored. The default value is zero.

param
rows the number of rows to fetch
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the condition rows >= 0 is not satisfied.
since
1.2
see
#getFetchSize

public voidsetMaxFieldSize(int max)
Sets the limit for the maximum number of bytes that can be returned for character and binary column values in a ResultSet object produced by this Statement object. This limit applies only to BINARY, VARBINARY, LONGVARBINARY, CHAR, VARCHAR, NCHAR, NVARCHAR, LONGNVARCHAR and LONGVARCHAR fields. If the limit is exceeded, the excess data is silently discarded. For maximum portability, use values greater than 256.

param
max the new column size limit in bytes; zero means there is no limit
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the condition max >= 0 is not satisfied
see
#getMaxFieldSize

public voidsetMaxRows(int max)
Sets the limit for the maximum number of rows that any ResultSet object generated by this Statement object can contain to the given number. If the limit is exceeded, the excess rows are silently dropped.

param
max the new max rows limit; zero means there is no limit
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the condition max >= 0 is not satisfied
see
#getMaxRows

public voidsetPoolable(boolean poolable)
Requests that a Statement be pooled or not pooled. The value specified is a hint to the statement pool implementation indicating whether the applicaiton wants the statement to be pooled. It is up to the statement pool manager as to whether the hint is used.

The poolable value of a statement is applicable to both internal statement caches implemented by the driver and external statement caches implemented by application servers and other applications.

By default, a Statement is not poolable when created, and a PreparedStatement and CallableStatement are poolable when created.

param
poolable requests that the statement be pooled if true and that the statement not be pooled if false

throws
SQLException if this method is called on a closed Statement

since
1.6

public voidsetQueryTimeout(int seconds)
Sets the number of seconds the driver will wait for a Statement object to execute to the given number of seconds. If the limit is exceeded, an SQLException is thrown. A JDBC driver must apply this limit to the execute, executeQuery and executeUpdate methods. JDBC driver implementations may also apply this limit to ResultSet methods (consult your driver vendor documentation for details).

param
seconds the new query timeout limit in seconds; zero means there is no limit
exception
SQLException if a database access error occurs, this method is called on a closed Statement or the condition seconds >= 0 is not satisfied
see
#getQueryTimeout