如果一個值等於另一個表中的值，請從其中一個表中選擇一個值

Question

有兩個mysql表games_server和orders_order。只有當該表中的值id等於第二個表orders_order的值server_id時，我需要從第一個表中選擇名爲full_address的值。

但不只是任何價值。它必須是WHERE service_type = 'be_first' AND status = 'running'

我讀到這裏可能的解決方案，並試圖這樣的事情：

SELECT server_address 
FROM games_server 
WHERE id IN 
    SELECT server_id 
    FROM orders_order 
    WHERE service_type = 'be_first' 
     AND status = 'running' 
ORDER BY updated DESC 

，但沒有奏效。我對mysql不太好。請幫忙。

Answer 1

SELECT a.thing you want to select 
    FROM table you want to select from AS a 
    JOIN the other table AS b 
    ON b.some column = a.some column 
WHERE some criterion is met 
    AND another criterion is met 

Answer 2

mysql_query("SELECT a.'full_address' FROM 'games_server' AS 'a' JOIN 'orders_order' AS 'b' ON b.'server_id' = a.'id' WHERE service_type = 'be_first' AND status = 'running'); 

是你有個大氣壓的代碼，我敢肯定它拋出一個錯誤。嘗試刪除AS關鍵字，以便它看起來像這樣：

mysql_query("SELECT a.'full_address' FROM 'games_server' a JOIN 'orders_order' b ON b.'server_id' = a.'id' WHERE service_type = 'be_first' AND status = 'running'); 

要讀出mysql的網站上的以下文章：https://dev.mysql.com/doc/refman/5.0/en/problems-with-alias.html

Answer 3

嘗試：

mysql_query("SELECT a.full_address FROM games_server AS a JOIN orders_order AS b ON b.server_id = a.id WHERE service_type = 'be_first' AND status = 'running'"); 

然後通過添加順序：

mysql_query("SELECT a.full_address FROM games_server AS a JOIN orders_order AS b ON b.server_id = a.id WHERE service_type = 'be_first' AND status = 'running' ORDER BY column_name");