MySQL的聯盟，並加入

Question

我有以下表

purchase_order   item 
------------------  ------------ 
id (PK)    id (PK) 
deleted    deleted 
name     name 
         purchase_order_id (FK) 

如何退還被鏈接到非缺失，非空PURCHASE_ORDER所有項目，以及沒有鏈接項目所有purchase_orders列表對他們來說，不管是否刪除。

如例如表

PURCHASE_ORDER

id name   deleted 
    --------------------------- 
    1  Big Sale  0 
    2  Other Sale 1 
    3  Empty Sale 0 

項目

id name   deleted purchase_order_id 
    ---------------------------------------------- 
    1  Fruit  1  1 
    2  Bread  0  1 
    3  Water  0  2 

正確的查詢給了我這樣的：

po_id name   item_id name 
------------------------------------ 
1  Big Sale  2  Bread 
3  Other Sale NULL  NULL 

編輯：這是我已經有了但親blem是，規定i.deleted = 0，則停止從返回

SELECT po.id, po.name, i.id, i.name 
FROM purchase_order po 
LEFT JOIN item i ON i.purchase_order_id=po.id 
WHERE po.deleted = 0 AND i.deleted = 0 

Answer 1

@strawberry不上的項目加入任何行給我的回答

SELECT po.id, po.name, i.id, i.name 
FROM purchase_order po 
LEFT JOIN item i ON i.purchase_order_id=po.id AND i.deleted = 0 
WHERE po.deleted = 0