sql插入数据的问题。求大神解答

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。

update tableA a,tableB b
set b.col2=a.col2,b.col3=a.col3
where a.id=b.id

update
table2 b
inner join
table1 c
using(字段1)
set
b.字段2=c.字段2,
b.字段3=c.字段3