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VAREXISTS function [Miscellaneous]

Function 

Returns 1 if a user-defined variable has been created or declared with a given name. Returns 0 if no such variable has been created.

Syntax 

VAREXISTS ( variable-name-string )

Parameters 

variable-name-string    The name to be tested, as a string.

Standards and compatibility 

• SQL/92    Vendor extension.

• SQL/99    Vendor extension.

• Sybase    Compatible with Adaptive Server Enterprise.

See also 

CREATE VARIABLE statement

DECLARE statement

IF statement

Example 

The following IF statement creates a variable with a name start_time if one is not already created or declared. The variable can then be used safely.

IF VAREXISTS('start_time') = 0 THEN
    CREATE VARIABLE start_time TIMESTAMP;
END IF;
SET start_time = current timestamp;