SQL Server sets the primary key from the growth column (implemented using SQL statements) _mssql

Source: Internet
Author: User
1. Create a new data table with field ID, set ID as primary key
Copy Code code as follows:

CREATE TABLE TB (ID int,constraint pkid primary key (ID))
CREATE table TB (ID int primary key)

2. Create a new data table with field ID, set ID as primary key and automatically number
Copy Code code as follows:

CREATE table TB (ID int identity (1,1), constraint Pkid primary key (ID))
CREATE table TB (ID int identity (1,1) primary key)

3. A data table has been built, which has the field ID, the ID set as the primary key
Copy Code code as follows:

ALTER TABLE TB ALTER COLUMN ID int NOT NULL
ALTER TABLE TB ADD constraint Pkid primary key (ID)

4. Delete primary key
Copy Code code as follows:

Declare @Pk VarChar (100);
Select @Pk =name from sysobjects where parent_obj=object_id (' TB ') and xtype= ' Pk ';
If @Pk is not null
EXEC (' Alter table TB Drop ' + @Pk)
Related Article

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.