借助 MAKE_SET() 函数，我们可以以整数偏移量列表的形式获取 MySQL SET 列值。为了便于理解，我们创建一个名为“set_testing”的表，如下所示 -
mysql> Create table set_testing( id INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT, table SET('ABC','ABD','GHF') NOT NULL);
Query OK, 0 rows affected (0.08 sec)
mysql> Insert into set_testing (table) values('1');
Query OK, 1 row affected (0.06 sec)
mysql> Insert into set_testing (table) values('2');
Query OK, 1 row affected (0.06 sec)
mysql> Insert into set_testing (table) values('3');
Query OK, 1 row affected (0.02 sec)
mysql> Insert into set_testing (table) values('4');
Query OK, 1 row affected (0.02 sec)
mysql> Select * from set_testing;
+----+---------+
| id | table |
+----+---------+
| 1 | ABC |
| 2 | ABD |
| 3 | ABC,ABD |
| 4 | GHF |
+----+---------+
4 rows in set (0.00 sec)现在，以下查询将获取 MySQL SET 列作为整数偏移量列表 -
mysql> Select MAKE_SET(types+0,'1','2','3') as output from doctypes1; +--------+ | output | +--------+ | 1 | | 2 | | 1,2 | | 3 | +--------+ 4 rows in set (0.00 sec)
