sql優化怎么做的?
這條語句還能怎么優化?大神們幫幫忙吧!謝謝
SELECT
a.*,
CASE
WHEN a.distno = '01' THEN
concat( DD.distname, '-合計' ) ELSE DD.distname?
END distname,
cast( ztyes/zts * 100 AS DECIMAL ( 8, 2 ) ) wcl,
2017 nf,
1 yf,
'' lx?
FROM
(
SELECT
ifnull( distno, '01' ) distno,
zts,
ztyes,
czs,
qyzs,
bfh?
FROM
(
SELECT
CASE
WHEN
( '01' ) = ( 4+3 ) THEN
a.linkDistId ELSE substring( a.linkDistId, 1, 4 )?
END distno,
count( DISTINCT a.acc_set ) zts,
count( DISTINCT b.acc_set ) ztyes,
count( DISTINCT CASE WHEN a.acc_style = '經濟帳' THEN b.acc_set END ) czs,
count( DISTINCT CASE WHEN a.acc_style = '企業帳' THEN b.acc_set END ) qyzs,
0 bfh?
FROM
gz_acc_set a
LEFT OUTER JOIN gz_balance b ON a.acc_set = b.acc_set?
AND b.years = 2017?
AND b.months = 1?
WHERE
a.dwlx LIKE
CASE
WHEN '' = ''?
OR '' = '全部' THEN
'%' ELSE ''?
END?
AND a.linkDistId LIKE '01%'?
GROUP BY
CASE
WHEN ( '01' ) = ( 4+3 ) THEN
a.linkDistId ELSE substring( a.linkDistId, 1, 4 )?
END WITH ROLLUP?
) a?
) a,
( SELECT distno, distname FROM scandist ) DD?
WHERE
DD.distno = a.distno
