MYSQL中模糊查询带逗号间隔的字符（FIND_IN_SET）_mysql 逗号分隔模糊查询

首先我们建立一张带有逗号分隔的字符串。  
CREATE TABLE test(id int(6) NOT NULL AUTO_INCREMENT,PRIMARY KEY (id),pname VARCHAR(20) NOT NULL,pnum VARCHAR(50) NOT NULL);  
  
然后插入带有逗号分隔的测试数据  
INSERT INTO test(pname,pnum) VALUES('产品1','1,2,4');  
INSERT INTO test(pname,pnum) VALUES('产品2','2,4,7');  
INSERT INTO test(pname,pnum) VALUES('产品3','3,4');  
INSERT INTO test(pname,pnum) VALUES('产品4','1,7,8,9');  
INSERT INTO test(pname,pnum) VALUES('产品5','33,4');  
  
  
查找pnum字段中包含3或者9的记录  
mysql> SELECT * FROM test WHERE find_in_set('3',pnum) OR find_in_set('9',pnum);  
+----+-------+---------+  
| id | pname | pnum    |  
+----+-------+---------+  
|  3 | 产品3 | 3,4     |  
|  4 | 产品4 | 1,7,8,9 |  
+----+-------+---------+  
2 rows in set (0.03 sec)  
  
  
使用正则  
mysql> SELECT * FROM test WHERE pnum REGEXP '(3|9)';  
+----+-------+---------+  
| id | pname | pnum    |  
+----+-------+---------+  
|  3 | 产品3 | 3,4     |  
|  4 | 产品4 | 1,7,8,9 |  
|  5 | 产品5 | 33,4    |  
+----+-------+---------+  
3 rows in set (0.02 sec)  
这样会产生多条记录，比如33也被查找出来了，不过MYSQL还可以使用正则，挺有意思的  
  
  
find_in_set()函数返回的所在的位置，如果不存在就返回0  
mysql> SELECT find_in_set('e','h,e,l,l,o');  
+------------------------------+  
| find_in_set('e','h,e,l,l,o') |  
+------------------------------+  
|                            2 |  
+------------------------------+  
1 row in set (0.00 sec)  
  
还可以用来排序，如下;  
mysql> SELECT * FROM TEST WHERE id in(4,2,3);  
+----+-------+---------+  
| id | pname | pnum    |  
+----+-------+---------+  
|  2 | 产品2 | 2,4,7   |  
|  3 | 产品3 | 3,4     |  
|  4 | 产品4 | 1,7,8,9 |  
+----+-------+---------+  
3 rows in set (0.03 sec)  
  
如果想要按照ID为4，2，3这样排序呢？  
mysql> SELECT * FROM TEST WHERE id in(4,2,3) ORDER BY find_in_set(id,'4,2,3');  
+----+-------+---------+  
| id | pname | pnum    |  
+----+-------+---------+  
|  4 | 产品4 | 1,7,8,9 |  
|  2 | 产品2 | 2,4,7   |  
|  3 | 产品3 | 3,4     |  
+----+-------+---------+  
3 rows in set (0.03 sec)   
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