MySQL存儲過程來檢查，如果用戶名退出

Question

我試圖創建一個存儲過程，它檢查是否在數據庫中存在或not.however用戶名，急診室

CREATE PROCEDURE `USER_EXISTS` 
(IN `GIVEN_USERNAME` VARCHAR(32)) 
BEGIN 
    SET @User_exists = 0; 
    SELECT COUNT(1) INTO @found 
    FROM `users` 
    WHERE `username` = `GIVEN_USERNAME` 
    IF @found > 0 THEN 
     SET @User_exists = 1 
    END IF 
    SELECT @User_exists 
END 

Answer 1

試試這個

CREATE PROCEDURE USER_EXISTS(IN GIVEN_USERNAME VARCHAR(32)) 
BEGIN 
    SET @User_exists = 0; 
    SELECT 1 INTO @User_exists 
    FROM users 
    WHERE username = GIVEN_USERNAME;  
    SELECT @User_exists 
END