MYSQL存儲過程2和表2選擇與1個更新請求發送到相同的表

Question

我有一個函數：

// Search user who have zero city but not zero country 
list($user_id, $country_id) = $site_db->query(" 
    select user_id, country_id 
    from users 
    WHERE city_id < 1 AND country_id > 1 
    LIMIT 1"); 

// If user found, get random city from user country 
if ($user_id > 0) 
{ 
    $random_city_query = $site_db->query(" 
    select id 
    from cities 
    WHERE country_id = $country_id 
    order by RAND() 
    limit 1"); 

// Update user city 
$update_city = $site_db->query(" 
    update users 
    set city_id = $random_city_query 
    WHERE user_id = $user_id"); 
} 

我嘗試該功能的基礎上創建MYSQL存儲過程。

我已經嘗試了一些變種，它不會工作:(

BEGIN 
update users u 
set u.city_id = (select ci.id from cities ci WHERE ci.country_id = u.country_id order by RAND() limit 1) 
WHERE user_id = (select u.user_id WHERE u.city_id < 1 AND u.country_id > 1 limit 1) 
END 

有人可以幫我

Answer 1

這種方式來創建存儲過程：

Create Procedure sp_ADD_RESPONSABLE_EXTRANET_CLIENT 
(
@ParLngId int output 
) 
as 
Begin 
if not exists (Select ParLngId from T_Param where ParStrIndex = 'RES' and ParStrP2 = 'Web') 
    Begin 
      INSERT INTO T_Param values('RES','¤ExtranetClient', 'ECli', 'Web', 1, 1, Null, Null, 'non', 'ExtranetClient', 'ExtranetClient', 25032, Null, 'informatique.interne@septeo.fr', 'Extranet-Client', Null, 27, Null, Null, Null, Null, Null, Null, Null, Null, 1, Null, Null, 0) 
      SET @ParLngId = @@IDENTITY 
    End 
Else 
    Begin 
      SET @ParLngId = (Select top 1 ParLngId from T_Param where ParStrNom = 'Extranet Client') 
      Return @ParLngId 
    End 
End 

Answer 2

所以，沒有人幫我:( 我花了2個多小時，自己創建程序:)

BEGIN 
SELECT @user_id := user_id from users WHERE city_id < 1 AND country_id > 1 LIMIT 1; 
IF NOT @user_id IS NULL 
THEN 
SELECT @user_country_id := country_id from users WHERE user_id = @user_id; 
SELECT @city_id := id from cities WHERE country_id = @user_country_id order by RAND() limit 1; 
update users set city_id = @city_id WHERE user_id = @user_id; 
END IF; 
END