SET

Description

This statement is used to set variables.

Syntax

SET [SESSION | GLOBAL] var_and_val_list;

var_and_val_list:
  var_and_val [,var_and_val ...]

var_and_val:
   var_value {TO | =} set_expr_or_default
 | var_value = (simple_select)

Parameters

Parameter	Description
SESSION | GLOBAL	Specifies whether to set a session-level or global variable. The default is session-level.
var_value	The name of the variable.

Examples

• Set the user variable a.

  SET @a = 1;

• Set the global system variable secure_file_priv, which specifies the path for importing or exporting files.

  SET GLOBAL secure_file_priv = '';

• Set the user variable proxy_route_policy, which is used to configure a routing policy.

  SET @proxy_route_policy = 'follower_first';

• Set the variable value by using the SELECT statement.

  CREATE TABLE tbl1(col INT);
  Query OK, 0 rows affected (0.049 sec)
  
  INSERT into tbl1 VALUES('1'),('2'),('3'),('4'),('5');
  Query OK, 5 rows affected (0.037 sec)
  Records: 5  Duplicates: 0  Warnings: 0
  
  SET @var1=(SELECT COUNT(*) FROM tbl1);
  Query OK, 0 rows affected (0.069 sec)