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SQL Anywhere 11.0.0 » SQL Anywhere Server - SQL Reference » Using SQL » SQL language elements » Variables

 

Local variables

SQL Anywhere supports local variables. Local variables are declared using the DECLARE statement, which can be used only within a compound statement (that is, bracketed by the BEGIN and END keywords). Only one variable can be declared for each DECLARE statement in SQL Anywhere.

If the DECLARE is executed within a compound statement, the scope is limited to the compound statement.

The variable is initially set as NULL. The value of the variable can be set using the SET statement, or can be assigned using a SELECT statement with an INTO clause.

The syntax of the DECLARE statement is as follows:

DECLARE variable-name data-type

Local variables can be passed as arguments to procedures, as long as the procedure is called from within the compound statement.

Examples

The following batch illustrates the use of local variables.

BEGIN
   DECLARE local_var INT;
   SET local_var = 10;
   MESSAGE 'local_var = ', local_var TO CLIENT;
END

Running this batch from Interactive SQL gives the message local_var = 10 in the Interactive SQL Messages tab.

The variable local_var does not exist outside the compound statement in which it is declared. The following batch is invalid, and gives a column not found error.

-- This batch is invalid.
BEGIN
   DECLARE local_var INT;
   SET local_var = 10;
END;
MESSAGE 'local_var = ', local_var TO CLIENT;

The following example illustrates the use of SELECT with an INTO clause to set the value of a local variable:

BEGIN
   DECLARE local_var INT;
   SELECT 10 INTO local_var;
   MESSAGE 'local_var = ', local_var TO CLIENT;
END

Running this batch from Interactive SQL gives the message local_var = 10 on the database server messages window.

For more information about batches and local variable scope, see Variables in Transact-SQL procedures.