if語句裏面的mysql查詢來確定表的選擇

Question

我想執行一個如果在查詢的中間顯示，我需要找出是否oc.product_type =='clothing'或'other'如果是是服裝，那麼我需要選擇特定服裝表而不是非服裝表？我真的有這個

SELECT o.total, o.shipping, o.order_date 
     ,oc.product_type, oc.product_id, oc.quantity, oc.price_per 
     ,cu.first_name, cu.last_name, CONCAT(cu.address1, cu.address2) AS address, 

//丟在這裏就是我嘗試如果

if(oc.product_type = 'clothing' 
     SELECT style 
     FROM specific_clothing 
     where oc.product_id = specific_clothing_id) as item 

    FROM order_contents AS oc 
    INNER JOIN `orders` as o ON oc.order_id = o.id 
    INNER JOIN `customers` AS cu ON o.customer_id=cu.id 
    WHERE o.customer_id = '214'; 

Answer 1

我認爲你只是在尋找增加一個外部聯接specific_clothing使用。事情是這樣的：

SELECT o.total, o.shipping, o.order_date 
     ,oc.product_type, oc.product_id, oc.quantity, oc.price_per 
     ,cu.first_name, cu.last_name, CONCAT(cu.address1, cu.address2) AS address 
     ,sc.style AS item 

    FROM order_contents AS oc 
    INNER JOIN `orders` as o ON oc.order_id = o.id 
    INNER JOIN `customers` AS cu ON o.customer_id=cu.id 
    LEFT OUTER JOIN specific_clothing sc ON (
     oc.product_id = sc.specific_clothing_id AND 
     oc.product_type = 'clothing') 
    WHERE o.customer_id = '214';