mysql> create table chartype_enum(
-> gender enum('男','女','保密','null')
-> )charset=utf8;
Query OK, 0 rows affected (1.76 sec)
mysql> insert into chartype_enum values('男');
Query OK, 1 row affected (0.00 sec)
mysql> insert into chartype_enum values('保密');
Query OK, 1 row affected (0.00 sec)
mysql> insert into chartype_enum values('女');
Query OK, 1 row affected (0.00 sec)
mysql> insert into chartype_enum values('remale');
Query OK, 1 row affected, 1 warning (0.00 sec)
mysql> insert into chartype_enum values('null');
Query OK, 1 row affected (0.00 sec)
mysql> select * from chartype_enum;
+--------+
| gender |
+--------+
| 男 |
| 保密 |
| 女 |
| |
| null |
+--------+
5 rows in set (0.00 sec)
mysql> select gender +0 from chartype_enum;
+-----------+
| gender +0 |
+-----------+
| 1 |
| 3 |
| 2 |
| 0 |
| 4 |
+-----------+
5 rows in set (0.00 sec)
mysql> alter table chartype_enum modify gender enum('男','女','保密');
Query OK, 5 rows affected, 1 warning (1.78 sec)
Records: 5 Duplicates: 0 Warnings: 1
mysql> select gender +0 from chartype_enum;
+-----------+
| gender +0 |
+-----------+
| 1 |
| 3 |
| 2 |
| 0 |
| 0 |
+-----------+
5 rows in set (0.00 sec)
mysql> delete from chartype_enum where gender=0;
Query OK, 2 rows affected (0.00 sec)
mysql> select * from chartype_enum;
+--------+
| gender |
+--------+
| 男 |
| 保密 |
| 女 |
+--------+
3 rows in set (0.00 sec)
-- 為什么插入數值出現錯誤呢？此處懷疑是洗掉列舉串列值時下標索引沒有更新，因此建議列舉串列更改需要慎重！！！
mysql> insert into chartype_enum values(2);
Query OK, 1 row affected (0.00 sec)
mysql> insert into chartype_enum values(3);
Query OK, 1 row affected (0.00 sec)
mysql> select * from chartype_enum;
+--------+
| gender |
+--------+
| 男 |
| 保密 |
| 女 |
| 保密 |
| 女 |
+--------+
5 rows in set (0.00 sec)
-- 此處以及之后又正常插入了，奇了怪了
mysql> insert into chartype_enum values(3);
Query OK, 1 row affected (0.00 sec)
mysql> select * from chartype_enum;
+--------+
| gender |
+--------+
| 男 |
| 保密 |
| 女 |
| 保密 |
| 女 |
| 保密 |
+--------+
6 rows in set (0.00 sec
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標籤：MySQL
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