How to change MySQL column definition?

问题

I have a mySQL table called test:

create table test(
    locationExpect varchar(120) NOT NULL;
);

I want to change the locationExpect column to:

create table test(
    locationExpect varchar(120);
);

How can it be done quickly?

回答1:

Do you mean altering the table after it has been created? If so you need to use alter table, in particular:

ALTER TABLE tablename MODIFY COLUMN new-column-definition

e.g.

ALTER TABLE test MODIFY COLUMN locationExpect VARCHAR(120);

回答2:

Syntax to change column name in MySql:

alter table table_name change old_column_name new_column_name data_type(size);

Example:

alter table test change LowSal Low_Sal integer(4);

回答3:

This should do it:

ALTER TABLE test MODIFY locationExpert VARCHAR(120) 

来源：https://stackoverflow.com/questions/1595372/how-to-change-mysql-column-definition