--标准的连接语句,Left join可以修改为join SELECT t1.*,t2.C_Field FROM TableA t1 LEFT JOIN TableB t2 ON t1.A_B =t2.A_B LEFT JOIN TableC t3 ON t2.B_C =t3.B_C
select a.*,c.c_field from TableA a left join TableB b on a.A_B = b.A_B left join TableC c on b.B_C = c.B_C
试试可以不