查询意外地花费了三倍的时间来执行：
SELECT p.rowid as 'promosk_rowid',s.id_pro as 'promosId',s.*,p.*,c.*,m.*
FROM promos s
LEFT JOIN promost t ON t.pro_prs=s.id_pro
LEFT JOIN promrule m ON m.pro_prr=s.id_pro
LEFT JOIN promosk p ON p.pro_psk=s.id_pro,coupons c
WHERE c.id_cpn=s.cpn_pro
AND c.typ_cpn='1'
AND c.act_cpn <> 'N'
AND s.act_pro <> 'N'
AND p.rowid IS NULL
AND t.rowid IS NULL
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') >= s.sd_pro
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') <= s.ed_pro
UNION
SELECT p.rowid as 'promosk_rowid',s.id_pro as 'promosId',s.*,p.*,c.*,m.*
FROM promos s
LEFT JOIN promost t ON t.pro_prs=s.id_pro
LEFT JOIN promrule m ON m.pro_prr=s.id_pro,promosk p,articles a,coupons c
WHERE s.id_pro=p.pro_psk
AND c.typ_cpn='1'
AND c.id_cpn=s.cpn_pro
AND c.act_cpn <> 'N'
AND s.act_pro <> 'N'
AND (a.article='0030269484')
AND (p.art_psk = a.article OR p.art_psk = '')
AND (p.coll_psk = a.collect OR p.coll_psk = '')
AND (p.type_psk = a.type_c OR p.type_psk = '')
AND (p.pat_psk = a.pat_c OR p.pat_psk = '')
AND (p.scl_psk = a.sclass_c OR p.scl_psk = '')
AND (p.cl1_psk = a.cl1_c OR p.cl1_psk = '')
AND (p.cl2_psk = a.cl2_c OR p.cl2_psk = '')
AND (p.ven_psk = a.model_c OR p.ven_psk = '')
AND (p.colr_psk = a.color_c OR p.colr_psk = '')
AND (p.siz_psk = a.size1 OR p.siz_psk = '')
AND (p.styl_psk = a.venitem OR p.styl_psk = '')
AND t.rowid IS NULL
AND p.rowid IS NOT NULL
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') >= s.sd_pro
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') <= s.ed_pro
UNION
SELECT p.rowid as 'promosk_rowid',s.id_pro as 'promosId',s.*,p.*,c.*,m.*
FROM promos s
LEFT JOIN promost t ON t.pro_prs=s.id_pro
LEFT JOIN promrule m ON m.pro_prr=s.id_pro
LEFT JOIN promosk p ON p.pro_psk=s.id_pro,coupons c,stores r
WHERE c.id_cpn=s.cpn_pro
AND c.typ_cpn='1'
AND c.act_cpn <> 'N'
AND s.act_pro <> 'N'
AND t.rowid IS NOT NULL
AND p.rowid IS NULL
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') >= s.sd_pro
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') <= s.ed_pro
AND r.st_num='218657'
AND (t.stc_prs = r.st_num OR t.stc_prs = '-1')
AND (t.clnt_prs = r.st_clnt OR t.clnt_prs = '-1')
UNION
SELECT p.rowid as 'promosk_rowid',s.id_pro as 'promosId',s.*,p.*,c.*,m.*
FROM promos s
LEFT JOIN promost t ON t.pro_prs=s.id_pro
LEFT JOIN promrule m ON m.pro_prr=s.id_pro,
promosk p,
articles a,
coupons c,
stores r
WHERE s.id_pro=p.pro_psk
AND c.typ_cpn='1'
AND c.id_cpn=s.cpn_pro
AND c.act_cpn <> 'N'
AND s.act_pro <> 'N'
AND (a.article='0030269484')
AND (p.art_psk = a.article OR p.art_psk = '')
AND (p.coll_psk = a.collect OR p.coll_psk = '')
AND (p.type_psk = a.type_c OR p.type_psk = '')
AND (p.pat_psk = a.pat_c OR p.pat_psk = '')
AND (p.scl_psk = a.sclass_c OR p.scl_psk = '')
AND (p.cl1_psk = a.cl1_c OR p.cl1_psk = '')
AND (p.cl2_psk = a.cl2_c OR p.cl2_psk = '')
AND (p.ven_psk = a.model_c OR p.ven_psk = '')
AND (p.colr_psk = a.color_c OR p.colr_psk = '')
AND (p.siz_psk = a.size1 OR p.siz_psk = '')
AND (p.styl_psk = a.venitem OR p.styl_psk = '')
AND t.rowid IS NOT NULL
AND p.rowid IS NOT NULL
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') >= s.sd_pro
AND STR_TO_DATE('2018-09-25','%Y-%m-%d') <= s.ed_pro
AND r.st_num='218657'
AND (t.stc_prs = r.st_num OR t.stc_prs = '-1')
AND (t.clnt_prs = r.st_clnt OR t.clnt_prs = '-1')
;
执行计划是：
+----+--------------+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+-------------------+-------+--------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+--------------+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+-------------------+-------+--------------------------------------+
| 1 | PRIMARY | c | ref | PRIMARY,typ_cpn | typ_cpn | 5 | const | 52 | Using where |
| 1 | PRIMARY | s | ref | cpn_pro | cpn_pro | 13 | pandora.c.id_cpn | 1 | Using where |
| 1 | PRIMARY | t | ref | pro_prs | pro_prs | 5 | pandora.s.id_pro | 25 | Using where; Using index; Not exists |
| 1 | PRIMARY | m | ref | pro_prr | pro_prr | 5 | pandora.s.id_pro | 1 | |
| 1 | PRIMARY | p | ref | pro_psk | pro_psk | 5 | pandora.s.id_pro | 781 | Using where; Not exists |
| 2 | UNION | a | const | PRIMARY,type_c,model_c,collect,color_c,pat_c,sclass_c,cl1_c,cl2_c,venitem,venitem__act,model_c__venitem__color_c,collect__venitem,model_c__venitem | PRIMARY | 12 | const | 1 | |
| 2 | UNION | p | ALL | rowid,pro_psk,art_psk | NULL | NULL | NULL | 34364 | Using where |
| 2 | UNION | s | eq_ref | PRIMARY,cpn_pro | PRIMARY | 4 | pandora.p.pro_psk | 1 | Using where |
| 2 | UNION | t | ref | pro_prs | pro_prs | 5 | pandora.p.pro_psk | 25 | Using where; Using index; Not exists |
| 2 | UNION | m | ref | pro_prr | pro_prr | 5 | pandora.p.pro_psk | 1 | |
| 2 | UNION | c | eq_ref | PRIMARY,typ_cpn | PRIMARY | 12 | pandora.s.cpn_pro | 1 | Using where |
| 3 | UNION | r | const | PRIMARY,st_clnt | PRIMARY | 4 | const | 1 | |
| 3 | UNION | c | ref | PRIMARY,typ_cpn | typ_cpn | 5 | const | 52 | Using where |
| 3 | UNION | s | ref | PRIMARY,cpn_pro | cpn_pro | 13 | pandora.c.id_cpn | 1 | Using where |
| 3 | UNION | m | ref | pro_prr | pro_prr | 5 | pandora.s.id_pro | 1 | |
| 3 | UNION | t | ref | rowid,pro_prs | pro_prs | 5 | pandora.s.id_pro | 25 | Using where |
| 3 | UNION | p | ref | pro_psk | pro_psk | 5 | pandora.t.pro_prs | 781 | Using where; Not exists |
| 4 | UNION | a | const | PRIMARY,type_c,model_c,collect,color_c,pat_c,sclass_c,cl1_c,cl2_c,venitem,venitem__act,model_c__venitem__color_c,collect__venitem,model_c__venitem | PRIMARY | 12 | const | 1 | |
| 4 | UNION | r | const | PRIMARY,st_clnt | PRIMARY | 4 | const | 1 | |
| 4 | UNION | p | ALL | rowid,pro_psk,art_psk | NULL | NULL | NULL | 34364 | Using where |
| 4 | UNION | s | eq_ref | PRIMARY,cpn_pro | PRIMARY | 4 | pandora.p.pro_psk | 1 | Using where |
| 4 | UNION | m | ref | pro_prr | pro_prr | 5 | pandora.p.pro_psk | 1 | |
| 4 | UNION | t | ref | rowid,pro_prs | pro_prs | 5 | pandora.p.pro_psk | 25 | Using where |
| 4 | UNION | c | eq_ref | PRIMARY,typ_cpn | PRIMARY | 12 | pandora.s.cpn_pro | 1 | Using where |
| NULL | UNION RESULT | <union1,2,3,4> | ALL | NULL | NULL | NULL | NULL | NULL | |
+----+--------------+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+-------------------+-------+--------------------------------------+
25 rows in set (0.19 sec)
使用InnoDB表会发生此问题。 任何其他信息，请让我知道。谢谢。