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How to modify the table structure of MySQL database? This problem may be often seen in our daily study or work. I hope you can gain a lot from this question. The following is the reference content that the editor brings to you, let's take a look at it!

MySQL database to modify the table structure methods: 1, use add to add fields, use drop to delete fields; 2, use alter to modify field names; 3, modify column types; 4, modify table names; 5, modify table options; 6, modify column properties.

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The method of modifying the table structure of MySQL database:

1. Add and delete fields

(1), add

Alter table table name add [column] field name column type column attribute [first | after field name]

(2), delete

Alter table table name drop [column] field name

two。 Modify field name

Statement: alter table table name change original field name new field name column type column attribute

Note: even if you only change the field name, then the original type of the field, the original property should be rewritten, otherwise it will be deleted.

3. Modify column type

Statement: alter table table name modify field name column type column attribute

4. Modify table name

Statement: alter table table name rename to new table name

5. Modify table options

Statement: alter table table name table option

Description: although MYSQL provides commands to modify table options, do not execute the command to modify the character set if there is already data in a table.

6. Modify column properties

Column properties include not null, default, unique, primary key, auto_increment

When a table is created, we can use the alter table table name modify to manipulate column properties. If the column properties are written during the operation, the

Is to add column properties, if not written is to delete column properties.

Special column properties: Primary key and unique.

Add column properties

Increase in general attributes:

Statement: alter table table name modify field name column type column attribute

Description:

When adding An and auto_increment, you should note that the field must be an integer, and it must be unique or primary key.

B, Unique and default cannot be used together.

The addition of primary key attributes:

Statement: alter table table name add primary key (field name)

Thank you for reading! After reading the above, do you have a general understanding of the method of modifying the table structure of the MySQL database? I hope the content of the article will be helpful to all of you. If you want to know more about the relevant articles, you are welcome to follow the industry information channel.

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