Drop FOREIGN KEY constraint from all table of database

while(exists(select 1 from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='FOREIGN KEY'))

begin

       declare @sql nvarchar(2000)

       SELECT TOP 1 @sql=('ALTER TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME

       + '] DROP CONSTRAINT [' + CONSTRAINT_NAME + ']')

       FROM information_schema.table_constraints

       WHERE CONSTRAINT_TYPE = 'FOREIGN KEY'

       exec (@sql)

end