sql插入数据的问题。求大神解答

Question

Answer 1

update
tableB B
join
(select * from tabalA A join tableB B on A.colum1=B.colum1) t
on
B.colum1 = t.colum1
set B.colum2=t.colum2,B.colum3=t.colum3, where B.colum1= 1;
where条件不给定则会将B表全部update。