Error 1317 mysql query execution interrupted 消息内容:查询执行被中断(数据库直接挂起)
1. 现象:
(1)在
PHP程序中使用子查询语句,导致Mysql自动“挂起”,即数据库“卡死”,程序不能正常运行
(2)在mysql命令行执行子查询语句,Mysql需要等待较长时间,提示 “ Error 1317 mysql query execution interrupted”
2. 处理办法有两种 :
006_kh表记录数目共计为 24256 条 uzone_2701_kh 表中记录数目共计为 52327条
原始SQL语句(子查询):
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SELECT count(kh_id) FROM `006_kh` WHERE kh_id in (select khbh from uzone_2701_kh where uzbh ='180' and jgm='27010899')
使用 desc 命令分析,结果如下:
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mysql>
mysql> desc SELECT count(kh_id) FROM `006_kh` WHERE kh_id in (select khbh from uzone_2701_kh where uzbh ='180' and jgm='27010899') ;
+----+--------------------+---------------+-------+---------------+---------+---------+------+-------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+--------------------+---------------+-------+---------------+---------+---------+------+-------+--------------------------+
| 1 | PRIMARY | 006_kh | index | NULL | PRIMARY | 4 | NULL | 89394 | Using where; Using index |
| 2 | DEPENDENT SUBQUERY | uzone_2701_kh | ALL | NULL | NULL | NULL | NULL | 24256 | Using where |
+----+--------------------+---------------+-------+---------------+---------+---------+------+-------+--------------------------+
2 rows in set (0.00 sec)
(1) 第一种方式:
sql脚本
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select count(kh_id) FROM `006_kh` where kh_id in(select khbh from (select khbh from uzone_2701_kh where uzbh ='180' and jgm='27010899') as khid_array)
使用 desc 命令分析,结果如下:
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mysql> desc select count(kh_id) FROM `006_kh` where kh_id in(select khbh from (select khbh from uzone_2701_kh where uzbh ='180' and jgm='27010899') as khid_array) ;
+----+--------------------+---------------+-------+---------------+---------+---------+------+-------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+--------------------+---------------+-------+---------------+---------+---------+------+-------+--------------------------+
| 1 | PRIMARY | 006_kh | index | NULL | PRIMARY | 4 | NULL | 96767 | Using where; Using index |
| 2 | DEPENDENT SUBQUERY | <derived3> | ALL | NULL | NULL | NULL | NULL | 24099 | Using where |
| 3 | DERIVED | uzone_2701_kh | ALL | NULL | NULL | NULL | NULL | 24256 | Using where |
+----+--------------------+---------------+-------+---------------+---------+---------+------+-------+--------------------------+
3 rows in set (0.02 sec)
(2)第二种方式 :
sql脚本 :
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select count(a.kh_id) from 011_kh a inner join uzone_2701_kh b on a.kh_id = b.khbh where b.uzbh ='180' and b.jgm='27010899'
使用 desc 命令分析,结果如下:
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mysql>
mysql> desc select count(a.kh_id) from 011_kh a inner join uzone_2701_kh b on a.kh_id = b.khbh where b.uzbh ='180' and b.jgm='27010899' ;
+----+-------------+-------+--------+---------------+---------+---------+--------------------+-------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+--------+---------------+---------+---------+--------------------+-------+-------------+
| 1 | SIMPLE | b | ALL | NULL | NULL | NULL | NULL | 24256 | Using where |
| 1 | SIMPLE | a | eq_ref | PRIMARY | PRIMARY | 4 | dxzs_v2_new.b.khbh | 1 | Using index |
+----+-------------+-------+--------+---------------+---------+---------+--------------------+-------+-------------+
2 rows in set (0.00 sec)
个人试验结论:使用JOIN语句的查询不一定总比使用子查询的语句快,根据我自己的试验结果和DESC分析结果 来说,还是JOIN语句比较快,效率比较高;因此,当使用in关键字进行子查询,效率低下时,强烈推荐第二种!
--转自