简单sql比较

[AshaChen]

--1
SELECT A, B, D
FROM LN_DAIKYINCHBILL L,
(SELECT COMNO
FROM DSTCOMPCTL
START WITH COMNO = #usrcomp#
CONNECT BY PRIOR COMNO = COMMAN) C
WHERE L.A = '10'
and L.B = C.COMNO;

--2
SELECT A, B, D
FROM LN_DAIKYINCHBILL L,
(SELECT COMNO
FROM DSTCOMPCTL
START WITH COMNO = #usrcomp#
CONNECT BY PRIOR COMNO = COMMAN) C
WHERE L.A = '10'
and L.B in C.COMNO;


---哪个的效率高 还是一样？
--是 and L.B = C.COMNO;
--还是 and L.B in C.COMNO;

[hanzs]

---哪个的效率高 还是一样？
1 效率高 具体看执行计划

--是 and L.B = C.COMNO;
--还是 and L.B in C.COMNO;
这个要看你业务需求

[pigengler]

L.B如果建立索引的话，肯定是 and L.B = C.COMNO; 效率更高，数据越多效果越明显