Drop Foreign Key without knowing the name of the constraint?

Question

I have created one table using below command:

create table Table1(
    Id int Not Null 
        Foreign key 
        references Table2(Id)  
        on delet         


        

Answer 1

A SQL Server option:

DECLARE @foreignkey varchar(100)
DECLARE @tablename varchar(100)
DECLARE @command nvarchar(1000)

DECLARE db_cursor CURSOR FOR
SELECT fk.name, t.name
FROM sys.foreign_keys fk
JOIN sys.tables t ON t.object_id = fk.parent_object_id
WHERE t.name IN (
    'table_1_name_here',
    'table_2_name_here'
)

OPEN db_cursor
FETCH NEXT FROM db_cursor INTO @foreignkey, @tablename
WHILE @@FETCH_STATUS = 0
BEGIN
    SELECT @command = 'ALTER TABLE ' + @tablename + ' DROP CONSTRAINT ' + @foreignkey
    EXECUTE(@command)
    FETCH NEXT FROM db_cursor INTO @foreignkey, @tablename
END
CLOSE db_cursor
DEALLOCATE db_cursor

The SQL selects all the constraints for the tables you care about into a cursor and drops them one by one. All you need to know are the names of the tables you want them dropped from.