我有一个表，其中包含用逗号分隔的URL列表。忽略应该更新架构的事实。以下两个语句均起作用：
SELECT id FROM website WHERE url LIKE '%example.com%';
SELECT id FROM website WHERE FIND_IN_SET('example.com', url);
有没有一种很好的方法来衡量查询的性能？有没有更好的方法（不更新架构）呢？
使用EXPLAIN，我得到以下结果：
+-------------+--------+---------+------+----------+
| select_type | type | key | rows | filtered |
+-------------+--------+---------+------+----------+
| SIMPLE | ALL | NULL | 5 | 20.00 | (LIKE)
| SIMPLE | ALL | NULL | 5 | 100.00 | (FIND_IN_SET)
+-------------+-------+----------+------+----------+
最佳答案
在MariaDB中，您可以在查询后用SET profiling=ON;和SHOW PROFILE;看到它。
样品
MariaDB [test]> SET profiling=ON;
Query OK, 0 rows affected (0.000 sec)
MariaDB [test]> SELECT FIND_IN_SET('2', '1,2,3,4,5');
+-------------------------------+
| FIND_IN_SET('2', '1,2,3,4,5') |
+-------------------------------+
| 2 |
+-------------------------------+
1 row in set (0.000 sec)
MariaDB [test]> SHOW PROFILE;
+--------------------------------+----------+
| Status | Duration |
+--------------------------------+----------+
| Starting | 0.000025 |
| Waiting for query cache lock | 0.000005 |
| Init | 0.000004 |
| Checking query cache for query | 0.000047 |
| Checking permissions | 0.000007 |
| Opening tables | 0.000011 |
| After opening tables | 0.000007 |
| Init | 0.000014 |
| Optimizing | 0.000012 |
| Executing | 0.000010 |
| End of update loop | 0.000005 |
| Query end | 0.000003 |
| Commit | 0.000004 |
| Closing tables | 0.000003 |
| Starting cleanup | 0.000004 |
| Freeing items | 0.000006 |
| Updating status | 0.000014 |
| Reset for next command | 0.000004 |
+--------------------------------+----------+
18 rows in set (0.000 sec)
MariaDB [test]>
关于mysql - MySQL列搜索逗号分隔的项目-FIND_IN_SET或LIKE，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/53723054/