How to modify column in mysql

Method: 1. Use the "alter table table name modify column column name dateType" statement to modify the data type; 2. Use the "alter table table name change old column name new column name type (length)" statement to modify the name. .

The operating environment of this tutorial: windows10 system, mysql8.0.22 version, Dell G3 computer.

How to modify column in mysql

1. Modify the data type of the field

 alter table table_name modify column column_name dateType

The example is as follows:

2. Modify the field name

alter table table_name change old_column_name new_column_name  int(11);

Expand knowledge:

1. Add a unique key

 alter table table_name add unique key `uniq_column` (`column`);

2. Add a field

alter table table_name add column column_name datatype

3. Delete a field

ALTER TABLE table_name DROP COLUMN column_name

4. Add a column

----alter table students add column 列名 列属性
alter table students 
    add column 语文 varchar(4) NOT NULL ;

----Add to the end of the column by default

after the name of the specified column name

First Add to the first column

Note: MySQL5.7.16 version does not seem to support Second, Third ...

# #

  alter table students 
    add column 数学 varchar(4) NOT NULL after 出生日期 ;

5. Delete columns

----alter table 表名 drop column 列名
alter table students drop column 成绩;

Recommended learning: mysql video tutorial

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