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处理mysql使用in关键字子查询1317错误_MySQL

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2016-06-01 13:35:161399浏览

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处理mysql使用in关键字子查询1317错误

 

    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):

[html] 

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:

[html] 

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

[html] 

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:

[html] 

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 |    | 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 :

[html] 

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: 

[html] 

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!

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