How can we change the table to add generated columns from MySQL storage?-Mysql Tutorial-php.cn

How can we change the table to add generated columns from MySQL storage?

王林

Release： 2023-09-10 12:33:03

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我们如何更改表以添加 MySQL 存储的生成列？

To add a generated column of MySQL storage in the table, we can use the same syntax as adding a column, just add "AS (expression)" after the data type That’s it. The syntax is as follows -

Grammar

ALTER TABLE table_name
ADD COLUMN column_name AS(expression)STORED;

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Example

mysql> ALTER TABLE employee_data_stored ADD COLUMN FULLName Varchar(200) AS (CONCAT_WS(" ", &#39;First_name&#39;,&#39;Last_name&#39;)) STORED;
Query OK, 2 rows affected (1.23 sec)
Records: 2 Duplicates: 0 Warnings: 0

mysql> Describe employee_data_stored;
+------------+--------------+------+-----+---------+------------------+
| Field      | Type         | Null | Key | Default | Extra            |
+------------+--------------+------+-----+---------+------------------+
| ID         | int(11)      | NO   | PRI | NULL    | auto_increment   |
| First_name | varchar(50)  | NO   |     | NULL    |                  |
| Last_name  | varchar(50)  | NO   |     | NULL    |                  |
| FULL_NAME  | varchar(90)  | YES  |     | NULL    | STORED GENERATED |
| FULLName   | varchar(200) | YES  |     | NULL    | STORED GENERATED |
+------------+--------------+------+-----+---------+------------------+
5 rows in set (0.00 sec)

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