MySQL CREATE USER 带有变量？

Question

我想这样做:

#Variables
SET @username="jdoe", @password="secret";

# Insert a new MySQL User
CREATE USER @username@'localhost' IDENTIFIED BY @password;GRANT USAGE ON *.* TO @username@'localhost' IDENTIFIED BY @password WITH MAX_QUERIES_PER_HOUR 120 MAX_CONNECTIONS_PER_HOUR 60 MAX_UPDATES_PER_HOUR 60 MAX_USER_CONNECTIONS 2;

但是得到:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@username@'localhost' IDENTIFIED BY @password' at line 2

如何在 CREATE USER 语句中使用变量？

Answer 1

你可以使用动态SQL作为:

SET @query1 = CONCAT('
        CREATE USER "',@username,'"@"localhost" IDENTIFIED BY "',@password,'" '
        );
PREPARE stmt FROM @query1; EXECUTE stmt; DEALLOCATE PREPARE stmt;

SET @query1 = CONCAT('
    GRANT USAGE ON *.* TO "',@username,'"@"localhost" IDENTIFIED BY "',@password,'" WITH
          MAX_QUERIES_PER_HOUR 120 MAX_CONNECTIONS_PER_HOUR 60 MAX_UPDATES_PER_HOUR 60 
          MAX_USER_CONNECTIONS 2'
        );
PREPARE stmt FROM @query1; EXECUTE stmt; DEALLOCATE PREPARE stmt;