I have the following two MySQL tables which I need to join:
A (donor) B (documents)
============ =============================
id | name id | profile_img | ref_id
------------ -----------------------------
1 | Alex 1 | a.png | 1
2 | Bill 2 | b.jpg | 2
3 | Cath 3 | c.jpg | 3
4 | Dale 4 | d.jpg | 4
5 | Evan
6 | Test
7 | Test2
SELECT d.name, d.id, c.name, c.ref_id FROM donor d, documents c WHERE
ref_id = d.id
問題是隻有那些記錄是在捐贈者表中休息不會顯示。我想在右側匹配未找到時始終顯示數據加入查詢的這些問題
首先,瞭解連接。然後,如果你還在掙扎,請看:[爲什麼我應該爲我認爲是非常簡單的SQL查詢提供一個MCVE?](https://meta.stackoverflow.com/questions/333952/why-should -i-provide-an-mcve-for-what-looks-to-what-seems-a-very-simple-sql-query) – Strawberry