SQL Server Deletes the default value constraint for a table

First isolate the default value constraint name for the field, and then delete the default value constraint based on the default value constraint name

Declare @constraintName varchar( $)Select @constraintName =B.name fromsyscolumns a,sysobjects bwherea.ID=object_id('Tb_kysubproject') andb.ID=A.cdefault andA.name='Final_belong_programme'  andB.name like 'df%'SELECT @constraintNameexec('ALTER TABLE tb_kysubproject drop constraint'+@constraintName)

Attention:

1.sql constraint prefix pk, UK, DF, CK, FK:

PK is primary key abbreviation, PRIMARY KEY constraint

UK is a unique key abbreviation, the only constraint

CK is a check abbreviation, checking constraints

FK is the foreign abbreviation, the primary foreign key relationship

DF is the default abbreviation, and defaults are constrained

2.syscolumns

cdefault :int the default value ID of the column.

ID:int the Table object ID that the column belongs to, or the stored procedure ID associated with the parameter.

Name :sysname The names of column names or procedure parameters.

3. object_id function

The function returns the ID value of the specified object

SQL Server Deletes the default value constraint for a table