Đặt thông báo tùy chỉnh cho giá trị ENUM trong MySQL

Sử dụng IF() để ánh xạ giá trị ENUM sang thông báo. Tạo bảng:

mysql> create table DemoTable1992 ( ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ClientName varchar(20), isActive ENUM('Y','N') ); Query OK, 0 rows affected (0.89 sec)

Thêm dữ liệu:

mysql> insert into DemoTable1992(ClientName,isActive) values('Chris','N'); Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable1992(ClientName,isActive) values('Bob','N'); Query OK, 1 row affected (0.08 sec)
mysql> insert into DemoTable1992(ClientName,isActive) values('David','Y'); Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable1992(ClientName,isActive) values('Carol','N'); Query OK, 1 row affected (0.19 sec)

Hiển thị dữ liệu:

mysql> select * from DemoTable1992;

+----------+------------+----------+
| ClientId | ClientName | isActive |
+----------+------------+----------+
| 1        | Chris      | N        |
| 2        | Bob        | N        |
| 3        | David      | Y        |
| 4        | Carol      | N        |
+----------+------------+----------+
4 rows in set (0.00 sec)

Truy vấn hiển thị thông báo tùy chỉnh:

mysql> select ClientName, if(isActive='Y', 'Active Member', 'Not Active Member') as Result from DemoTable1992;

Kết quả:

+------------+-------------------+
| ClientName | Result            |
+------------+-------------------+
| Chris      | Not Active Member |
| Bob        | Not Active Member |
| David      | Active Member     |
| Carol      | Not Active Member |
+------------+-------------------+
4 rows in set (0.00 sec)