How to drop all Foreign Key constraints in all tables?

Question

I want to write sql command to drop all constraints in all tables. I searched on the internet and found the following which works fine if the database is small and not compl

Answer 1

I used the INFORMATION_SCHEMA solution mentioned by @Yaroslav, but had too many foreign key constants in my database to fit them all into a varchar(MAX). So I had to modify the script to use a temporary table and a cursor instead.

Also, I added [] around the table name.

DECLARE @SQL TABLE (Command VARCHAR(MAX))

INSERT @SQL
SELECT 'ALTER TABLE [' + FK.TABLE_NAME + '] DROP CONSTRAINT [' + RTRIM(C.CONSTRAINT_NAME) +'];' + CHAR(13)
  FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
 INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
    ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
 INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
    ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
 INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU
    ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
 INNER JOIN (
            SELECT i1.TABLE_NAME, i2.COLUMN_NAME
              FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
             INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2
                ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
            WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
           ) PT
    ON PT.TABLE_NAME = PK.TABLE_NAME

DECLARE cmdCursor CURSOR
    FOR SELECT Command FROM @SQL
OPEN cmdCursor
DECLARE @Command VARCHAR(MAX)

FETCH NEXT FROM cmdCursor INTO @Command
WHILE @@FETCH_STATUS = 0
BEGIN
    PRINT @Command
    EXEC (@Command)
    FETCH NEXT FROM cmdCursor INTO @Command
END

CLOSE cmdCursor;
DEALLOCATE cmdCursor;