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)
