How to modify field type in MySQL?

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How to modify field type in MySQL?

2024-07-17 09:26| 来源: 网络整理| 查看: 265

In MySQL, you can modify the data type of a field in the table through the alter table statement. The following article will take you through the alter table statement and introduce how to modify the field type. I hope it will be helpful to you.

How to modify field type in MySQL?

In MySQL, the alter table statement is used to add, modify, or delete columns (fields) in an existing table.

1. Add a field (column)

alter table 表名 add 字段名 数据类型Copy after login

Example: Add a field named The new column of "Birthday", the data type is "date"

alter table Persons add Birthday dateCopy after login

Description: The type of the new column "Birthday" is date, which can store dates

2. Modification Field name

alter table 表名 rename column A to BCopy after login

3. Modify field type

alter table 表名 alter column 字段名 数据类型Copy after login

Example: Change the table" The data type of the "Birthday" column in Persons" is changed to "year"

alter table Persons alter column Birthday yearCopy after login

Explanation: The data type of the "Birthday" column is year, which can store the year in 2-digit or 4-digit format.

4. Delete fields

alter table 表名 drop column 字段名Copy after login

Example:Delete the "Birthday" column in the "Person" table

alter table Persons drop column BirthdayCopy after login

Related video tutorial recommendations: "MySQL Tutorial"

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