SELECT * ,
(SELECT TOP 1 rk_js
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_js,
(SELECT TOP 1 rk_sl
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_sl,
(SELECT TOP 1 suolv
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS suolv
FROM T
这样查出来是17900条记录,耗时3秒
但是要加上条件之后
SELECT * ,
(SELECT TOP 1 rk_js
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_js,
(SELECT TOP 1 rk_sl
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_sl,
(SELECT TOP 1 suolv
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS suolv
FROM T where lpdate between '2010-03-01' and '2010-03-31'
这样查询要耗时一分多钟,
sql 2000的数据库,在2005中好像快多了
(SELECT TOP 1 rk_js
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_js,
(SELECT TOP 1 rk_sl
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_sl,
(SELECT TOP 1 suolv
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS suolv
FROM T
这样查出来是17900条记录,耗时3秒
但是要加上条件之后
SELECT * ,
(SELECT TOP 1 rk_js
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_js,
(SELECT TOP 1 rk_sl
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS rk_sl,
(SELECT TOP 1 suolv
FROM rkd_main
WHERE T.lpph=rkd_main.lp_ph AND
T.pb_gg = rkd_main.guige) AS suolv
FROM T where lpdate between '2010-03-01' and '2010-03-31'
这样查询要耗时一分多钟,
sql 2000的数据库,在2005中好像快多了
解决方案 »
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