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SQL Anywhere 11.0.0 » SQL Anywhere Server - SQL Reference » Using SQL » SQL statements » SQL statements (P-Z)

 

SET statement [T-SQL]

Use this statement to set database options for the current connection in an Adaptive Server Enterprise-compatible manner.

Syntax
SET option-name option-value
Remarks

The available options are as follows:

Option name Option value
ansinull On or Off
ansi_permissions On or Off
close_on_endtrans On or Off
datefirst

1, 2, 3, 4, 5, 6, or 7

The setting of this option affects the DATEPART function when obtaining a weekday value.

For more information about specifying the first day of the week, see first_day_of_week option [database] and DATEPART function [Date and time].

quoted_identifier On | Off
rowcount integer
self_recursion On | Off
string_rtruncation On | Off
textsize integer
transaction isolation level 0, 1, 2, 3, snapshot, statement snapshot, or read only statement snapshot

Database options in SQL Anywhere are set using the SET OPTION statement. However, SQL Anywhere also provides support for the Adaptive Server Enterprise SET statement for options that are particularly useful for compatibility.

The following options can be set using the Transact-SQL SET statement in SQL Anywhere, as well as in Adaptive Server Enterprise:

  • SET ansinull { On | Off }   The default behavior for comparing values to NULL is different in SQL Anywhere and Adaptive Server Enterprise. Setting ansinull to Off provides Transact-SQL compatible comparisons with NULL.

    SQL Anywhere also supports the following syntax:

    SET ansi_nulls { On | Off }

    For more information, see ansinull option [compatibility].

  • SET ansi_permissions { On | Off }   The default behavior is different in SQL Anywhere and Adaptive Server Enterprise regarding permissions required to carry out an UPDATE or DELETE containing a column reference. Setting ansi_permissions to Off provides Transact-SQL-compatible permissions on UPDATE and DELETE. See ansi_permissions option [compatibility].

  • SET close_on_endtrans { On | Off }   The default behavior is different in SQL Anywhere and Adaptive Server Enterprise for closing cursors at the end of a transaction. Setting close_on_endtrans to Off provides Transact-SQL compatible behavior. See close_on_endtrans option [compatibility].

  • SET datefirst { 1 | 2 | 3 | 4 | 5 | 6 | 7 }   The default is 7, which means that the first day of the week is by default Sunday. To set this option permanently, see first_day_of_week option [database].

  • SET quoted_identifier { On | Off }   Controls whether strings enclosed in double quotes are interpreted as identifiers (On) or as literal strings (Off). See Setting options for Transact-SQL compatibility and quoted_identifier option [compatibility].

  • SET rowcount   integer The Transact-SQL ROWCOUNT option limits the number of rows fetched for any cursor to the specified integer. This includes rows fetched by re-positioning the cursor. Any fetches beyond this maximum return a warning. The option setting is considered when returning the estimate of the number of rows for a cursor on an OPEN request.

    SET ROWCOUNT also limits the number of rows affected by a searched UPDATE or DELETE statement to integer. This might be used, for example, to allow COMMIT statements to be performed at regular intervals to limit the size of the rollback log and lock table. The application (or procedure) would need to provide a loop to cause the update/delete to be re-issued for rows that are not affected by the first operation. A simple example is given below:

    BEGIN
       DECLARE @count INTEGER
       SET rowcount 20
       WHILE(1=1) BEGIN
          UPDATE Employees SET Surname='new_name'
          WHERE Surname <> 'old_name'
          /* Stop when no rows changed */
          SELECT @count = @@rowcount
          IF @count = 0 BREAK
          PRINT string('Updated ',
                   @count,' rows; repeating...')
          COMMIT
       END
       SET rowcount 0
    END

    In SQL Anywhere, if the ROWCOUNT setting is greater than the number of rows that Interactive SQL can display, Interactive SQL may do some extra fetches to reposition the cursor. Thus, the number of rows actually displayed may be less than the number requested. Also, if any rows are re-fetched due to truncation warnings, the count may be inaccurate.

    A value of zero resets the option to get all rows.

  • SET self_recursion { On | Off }   The self_recursion option is used within triggers to enable (On) or prevent (Off) operations on the table associated with the trigger from firing other triggers.

  • SET string_rtruncation { On | Off }   The default behavior is different between SQL Anywhere and Adaptive Server Enterprise when non-space characters are truncated during assignment of SQL string data. Setting string_rtruncation to On provides Transact-SQL-compatible string comparisons. See string_rtruncation option [compatibility].

  • SET textsize   Specifies the maximum size (in bytes) of text or image type data to be returned with a select statement. The @@textsize global variable stores the current setting. To reset to the default size (32 KB), use the command:
    set textsize 0

  • SET transaction isolation level { 0 | 1 | 2 | 3 | snapshot | statement snapshot | read only statement snapshot }   Sets the locking isolation level for the current connection, as described in Isolation levels and consistency. For Adaptive Server Enterprise, only 1 and 3 are valid options. For SQL Anywhere, any of 0, 1, 2, 3, snapshot, statement snapshot, and read only statement snapshot is a valid option. See isolation_level option [compatibility].

The SET statement is allowed by SQL Anywhere for the prefetch option, for compatibility, but has no effect.

Permissions

None.

Side effects

None.

See also
Standards and compatibility
  • SQL/2003   Transact-SQL extension.