mysql 存储过程中if

IF condition THEN
    -- SQL statements when condition is TRUE
ELSE
    -- SQL statements when condition is FALSE
END IF;

DELIMITER //

CREATE PROCEDURE UpdateUserStatus(IN userId INT, IN newStatus VARCHAR(20))
BEGIN
    DECLARE userCurrentStatus VARCHAR(20);
    
    -- 获取用户当前状态
    SELECT status INTO userCurrentStatus FROM users WHERE id = userId;
    
    -- 根据当前状态和新状态执行不同的操作
    IF userCurrentStatus = 'active' AND newStatus = 'inactive' THEN
        UPDATE users SET status = newStatus WHERE id = userId;
        SELECT 'User status updated to inactive.' AS message;
    ELSEIF userCurrentStatus = 'inactive' AND newStatus = 'active' THEN
        UPDATE users SET status = newStatus WHERE id = userId;
        SELECT 'User status updated to active.' AS message;
    ELSE
        SELECT 'No status change needed.' AS message;
    END IF;
END //

DELIMITER ;