Database-Add a column of commands to the original table

Source: Internet
Author: User
MySQL adds a column of commands to a table in one place

If you want to add a column to a table that has already been built, you can use the following example:

ALTER TABLE t1 add column addr varchar (a) not null;

This statement adds a column of addr to the existing table T1, which is the last column in the table. If we want to add a column in the specified, you can use:

ALTER TABLE t1 add column addr varchar (NO) null after User1;

Note that the above command means adding addr to the column after User1. If you want to add to the first column, you can use:

ALTER TABLE t1 add column addr varchar (a) not NULL first;

Database-Add a column of commands to the original table (GO)

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.