MySQL TẠO NGƯỜI DÙNG với biến?

Question

Tôi muốn làm điều này:

#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; 

Nhưng nhận được:

#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 

Làm thế nào để sử dụng một biến trong câu lệnh CREATE USER?

Answer 1

Bạn có thể sử dụng dynamic SQL như:

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;