MySQL內部聯接以更新現有表

Question

我有一個名為empty的表，如下所示，該表僅具有paperkey值，其他所有內容均為空。

author | year | conference | paperkey
                               1234

我還有另一個稱為base表，如下所示：

author | year | conference | paperkey
Andrew   1999     KDD           1234

我想將在表base檢索到的值插入表empty 。

我嘗試查詢如下，但是沒有用。 如何修改此查詢以獲得正確的結果？

insert into empty (author, year, conference)
select T1.author, T1.year, T1.conference
from base as T1
inner join empty as T2 on T1.paperkey=T2.paperkey;

Answer 1

我認為您正在尋找基於paperkey empty更新

update empty e
join base b on b.paperkey = e.paperkey
set 
e.author = b.author,
e.year = b.year,
e.conference = b.conference

Answer 2

您想更新現有記錄，而不是插入新記錄。

update empty T2
join base T1 on T1.paperkey = T2.paperkey
set T2.author = T1.author,
    T2.year = T1.year,
    T2.conference = T1.conference