SET

Initializes the value of a session variable to the result of a SQL expression.

See also:

SHOW VARIABLES , UNSET

Syntax

SET <var> = <expr>

SET ( <var> [ , <var> ... ] )  = ( <expr> [ , <expr> ... ] )

Parameters

var

Specifies the identifier for the variable to initialize.

expr

Specifies the SQL expression for the variable.

Usage notes

  • You can set multiple variables in the same statement.
  • If you specify complex expressions, a running virtual warehouse might be required in the session.
  • The number of expressions must match the number of variables to initialize.
  • The size of string or binary variables is limited to 256 bytes.
  • The identifier (i.e. name) for a SQL variable is limited to 256 characters.
  • Variable names such as CURRENT or PUBLIC are reserved for future use by Snowflake and cannot be used.

Examples

These two examples use constants to set variables:

SET V1 = 10;

SET V2 = 'example';

This example sets more than one variable at a time:

SET (V1, V2) = (10, 'example');

This example sets the variable to the value of a non-trivial expression that uses a SQL query:

SET id_threshold = (SELECT COUNT(*)/2 FROM table1);

The following example shows the result when a SET command evaluates all of the expressions on the right-hand side of the assignment operator before setting the first expression on the left-hand side of the operator. Note that the value of the variable named max is set based on the old value of min, not the new value.

SET (min, max) = (40, 70);
SET (min, max) = (50, 2 * $min);

SELECT $max;
+------+
| $MAX |
|------|
|   80 |
+------+