CREATE VARIABLE Statement

Creates a SQL variable.

Syntax

CREATE 
[OR REPLACE] 
VARIABLE 
identifier data-type 
[{= | DEFAULT} 
initial-value]

Parameters

Examples

Usage

The CREATE VARIABLE statement creates a new variable of the specified data type. If you specify initial-value, the variable is set to that value. If you do not specify initial-value, the variable contains the NULL value until a SET statement assigns a different value.

Specifying the OR REPLACE clause drops the named variable if it already exists and replaces its definition. You can use the OR REPLACE clause as an alternative to the VAREXISTS function in SQL scripts.

A variable can be used in a SQL expression anywhere a column name is allowed. If a column name exists with the same name as the variable, the variable value is used.

A variable can be used in a SQL expression anywhere a column name is allowed. Name resolution is performed as follows:
  • Match any aliases specified in the query's SELECT list.
  • Match column names for any referenced tables.
  • Assume the name is a variable.

Variables belong to the current connection, and disappear when you disconnect from the database, or when you use the DROP VARIABLE statement. Variables are not visible to other connections. COMMIT or ROLLBACK statements do not affect variables.

Variables created with the CREATE VARIABLE statement persist for a connection even when the statement is issued within a (BEGIN...END) statement. You must use DECLARE to create variables that only persist within a (BEGIN...END) statement, for example, within stored procedures.

Variables are useful for creating large text or binary objects for INSERT or UPDATE statements from Embedded SQL programs.

Local variables in procedures and triggers are declared within a compound statement. See System Administration Guide: Volume 2 > Using Procedures and Batches > Control Statements > Using Compound Statements.

If you specify initial-value, the data type must match the type defined by data-type.

See also Reference: Building Blocks, Tables, and Procedures > SQL Data Types.

Standards

  • SQL—Vendor extension to ISO/ANSI SQL grammar.

  • Sybase—Not supported by Adaptive Server Enterprise.

Permissions

None

Related reference
BEGIN … END Statement
DECLARE Statement
DROP VARIABLE Statement
SET Statement [ESQL]