Question

SQL中多表关联赋值语句怎么写

A表有 d,e 两列，B表有j,k 两列，C表有m,n两列，其中e和j关联，k和m关联，现在想把n的值赋予给d

Answer 1

update a set a.e=c.n from a left join b on a.e=b.j left join c on b.k=c.m

Answer 2

update a set a.e = c.n
where a.e = b.j and b.k = c.m