INSERT ...在MySQL

Question

SELECT查詢我有兩個表：

`user1` 
- full_name 
- headline # this is empty 

`user2` 
- full_name 
- headline # this has content 

我想從user2表中插入headline到user1表。這是我到目前爲止有：

insert into user1 set headline = (select headline from user2 where headline=headline) 

不過，我得到一個錯誤信息，從該說的select返回多行。我將如何正確地發出這個插入語句？

Answer 1

這並不完全清楚你想要做什麼。特別是當每個表中有多個記錄時會發生什麼？如果你想從user2標題複製到user1其中full_name比賽中，你可以使用多臺UPDATE語法來聯接表並更新user1：

UPDATE user1 JOIN user2 USING (full_name) SET user1.headline = user2.headline 

Answer 2

如果你真的想要一個INSERT那麼你要

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如果你確實要更新，那麼你想

UPDATE user1 SET headline = (SELECT headline FROM user2 WHERE user1.full_name = user2.full_name)