sql关联查询，子查询的优化

项目中接收离职同事的统计部分代码的优化，客户反映随着时间查询越来越慢，最长的到了5分钟左右，客户当然反馈很强烈，系统太不稳定了，反映越来越慢。。。，不多说直接上sql代码

SELECT ajjbxx.ssbm, pqNum
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE 20 - ISNULL(gzNum, 0) * 20.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) + round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE 20 - (ISNULL(fgNum, 0) + ISNULL(fgNum2, 0)) * 20.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) + round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(aqNum, 0) * 40.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) + round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(clfkNum, 0) * 20.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS df
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE 20 - ISNULL(gzNum, 0) * 20.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS gzldf
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(gzNum, 0) * 100.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS gzl
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE 20 - (ISNULL(fgNum, 0) + ISNULL(fgNum2, 0)) * 20.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS fgldf
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE (ISNULL(fgNum, 0) + ISNULL(fgNum2, 0)) * 100.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS fgl
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(aqNum, 0) * 40.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS aqczldf
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(aqNum, 0) * 100.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS aqczl
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(clfkNum, 0) * 20.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS czldf
, round(CASE
WHEN ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) = 0 THEN 1
ELSE ISNULL(clfkNum, 0) * 100.00 / (ISNULL(pqNum, 2) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0))
END, 2) AS czl
, ISNULL(pqNum, 0) - ISNULL(zfNum, 0) - ISNULL(jyNum, 0) AS yczNum
, zzjg.dwmc, clfkNum, htNum, aqNum, cqNum
, ISNULL(fgNum, 0) + ISNULL(fgNum2, 0) AS fgNum
, clzNum, zpqNum, zhtNum, zfNum, gzNum
, cqwclNum
FROM (
SELECT *
FROM t_ajjbxxb
) ajjbxx
LEFT JOIN (
SELECT *
FROM t_zzjgb
) zzjg
ON zzjg.zzbh = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS pqNum, a.ssbm
FROM (
SELECT ajbh, ssbm, lcbh, sbsj
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '344D8F3F-8FA8-403C-AEBD-C663008BFBAA'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm, ajbh, ssbm, lcbh, sbsj
) a
GROUP BY ssbm
) pq
ON pq.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS zfNum, a.ssbm
FROM (
SELECT ajbh, ssbm, lcbh, sbsj
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = 'B9AB809C-87D5-41F9-9520-48980DFA289F'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm, ajbh, ssbm, lcbh, sbsj
) a
GROUP BY ssbm
) zf
ON zf.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS gzNum, a.ssbm
FROM (
SELECT ajbh, ssbm, lcbh, sbsj
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '92D1D71F-274D-4423-8372-0B094DB50A16'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm, ajbh, ssbm, lcbh, sbsj
) a
GROUP BY ssbm
) gz
ON gz.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS jyNum, a.ssbm
FROM (
SELECT ajbh, ssbm, lcbh, sbsj
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = 'A85A6190-B0DB-4C09-AB94-E386C29A1D74'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm, ajbh, ssbm, lcbh, sbsj
) a
GROUP BY ssbm
) jy
ON jy.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS htNum, ssbm
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '5BDE3C96-C04E-4779-9F78-2287318E2F95'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm
) ht
ON ht.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS zpqNum
FROM (
SELECT COUNT(1) AS zzpqNum, ajbh
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '344D8F3F-8FA8-403C-AEBD-C663008BFBAA'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ajbh
) pq1
) zpq
ON 1 = 1
LEFT JOIN (
SELECT COUNT(1) AS zhtNum
FROM (
SELECT COUNT(1) AS zzhtNum, ajbh
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '5BDE3C96-C04E-4779-9F78-2287318E2F95'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ajbh
) ht1
) zht
ON 1 = 1
LEFT JOIN (
SELECT COUNT(1) AS clfkNum, ssbm
FROM (
SELECT ssbm, ajbh
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '9ADFAB81-96A6-4F5A-8E18-3ECA98CD65F7'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm, ajbh
) a
GROUP BY ssbm
) clfk
ON clfk.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS clzNum, ssbm
FROM t_ajjbxxb WITH (NOLOCK)
WHERE ajzt <> 'CE5B6B41-7B67-4476-884A-8590418F4DB7'
AND ajzt <> '19486445-BD8E-49D6-B635-DDD4A8783F5F'
AND ajzt <> '71668A4F-DC41-48FB-B911-2FF8AB9C5C4E'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm
) clz
ON clz.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS aqNum, aq1.ssbm
FROM (
SELECT a.ajbh, a.ssbm
FROM (
SELECT *
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '9ADFAB81-96A6-4F5A-8E18-3ECA98CD65F7'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
) a
LEFT JOIN (
SELECT *
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '45CDC555-B94D-4844-9B43-F2D20D87FE24'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
) b
ON a.ajbh = b.ajbh
WHERE a.ajbh = b.ajbh
AND a.blqx > b.fqsj
AND a.sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY a.ssbm, a.ajbh
EXCEPT
SELECT a.ajbh, a.ssbm
FROM (
SELECT *
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '9ADFAB81-96A6-4F5A-8E18-3ECA98CD65F7'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
) a
LEFT JOIN (
SELECT *
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '45CDC555-B94D-4844-9B43-F2D20D87FE24'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
) b
ON a.ajbh = b.ajbh
WHERE a.ajbh = b.ajbh
AND a.blqx < b.fqsj
AND a.sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY a.ssbm, a.ajbh
) aq1
GROUP BY aq1.ssbm
) aq
ON aq.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS cqwclNum, ssbm
FROM t_ajjbxxb WITH (NOLOCK)
WHERE getdate() > blqx
AND ajzt <> 'CE5B6B41-7B67-4476-884A-8590418F4DB7'
AND ajzt <> '19486445-BD8E-49D6-B635-DDD4A8783F5F'
AND ajzt <> '71668A4F-DC41-48FB-B911-2FF8AB9C5C4E'
AND ajzt <> 'E48625AA-4859-41AF-9570-30FD0F721BF6'
AND ajzt <> '48A8DCC5-CF36-45B8-B575-D538C1D3C996'
AND ajzt <> '85404CD0-ADA1-458B-AEE7-AB2BABDE15FA'
AND ajzt <> '78F6852F-BFC0-4CEA-B0F1-223F48F7FCA1'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY ssbm
) cqwcl
ON cqwcl.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS cqNum, ssbm
FROM (
SELECT a.ajbh, a.ssbm
FROM (
SELECT *
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '9ADFAB81-96A6-4F5A-8E18-3ECA98CD65F7'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
) a
LEFT JOIN (
SELECT *
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '45CDC555-B94D-4844-9B43-F2D20D87FE24'
AND ajzt <> 'ED2E7CD7-F65D-40CE-8766-5898C51B23ED'
) b
ON a.ajbh = b.ajbh
WHERE a.ajbh = b.ajbh
AND a.blqx < b.fqsj
AND a.sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
GROUP BY a.ssbm, a.ajbh
) aq1
GROUP BY aq1.ssbm
) cq
ON cq.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS fgNum, ssbm
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '2442A76F-BB18-431F-AA2C-F1EFEF5A38FE'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
AND sbsj < '20180126'
GROUP BY ssbm
) fg
ON fg.ssbm = ajjbxx.ssbm
LEFT JOIN (
SELECT COUNT(1) AS fgNum2, ajbmbh
FROM (
SELECT MAX(ajbh) AS ajbh, ajbmbh
FROM V_ajlcb WITH (NOLOCK)
WHERE lcbh = '2442A76F-BB18-431F-AA2C-F1EFEF5A38FE'
AND sbsj BETWEEN '2018/3/15 0:00:00' AND '2018/3/15 23:59:59'
AND sbsj >= '20180126'
GROUP BY ajbmbh, ajbh
) fgcs
GROUP BY ajbmbh
) fg2
ON fg2.ajbmbh = ajjbxx.ssbm
WHERE ajjbxx.ssbm <> ''
AND zzjg.dwmc <> ''
GROUP BY zpqNum, zhtNum, ajjbxx.ssbm, pqNum, zzjg.dwmc, clfkNum, htNum, aqNum, fgNum, fgNum2, clzNum, cqNum, zfNum, gzNum, jyNum, cqwclNum
ORDER BY yczNum DESC

这段sql主要是通过关联查询嵌套子查询，同时有分组和排序要求，关联的表里面有视图（视图有记录表t_ajlcb和基本表t_ajjbxxb组成,以及其他字典表，基础数据表），所有表的数量大概10个表左右，记录表（视图）数据大概有15万条，基本表有1万多条。

查询时间大概是50秒到5分钟之间，开始分析原因：

1、查看sql执行计划，发现视图里面的t_ajlcb和t_ajjbxxb的表都是全表搜索，每个查询t_ajlcb占到了4%，t_ajjbxxb占2%这样下来12个子查询或者关联查询效率就到了（4%+2%）*10=72%，其他的就是排序排序占的效率高一点。很明显影响效率的就是因为两个数据比较多的表未做索引，接下来需要给他们选择合适的索引。

2、先看看这两个表的查询的字段是什么，然后再确定查询条件，本例中两个表最终统计的ajbh,ssbm这两个字段，查询条件已时间段为主，因此我们选择给这两个表分别创建聚集索引，创建什么样的索引根据个人的理解和经验，当然有一些原则，例如下图：

sql关联查询，子查询的优化