Question

This is going to sound like a crazy request. The databases that I report from do not have any foreign keys, and every single primary key is an identity_column. This makes using tools such as TOAD difficult because the Intellisense works by reading the PK and FK relationships.

Anyone have a script to remove the primary keys from every table in the database so I can replace them with “correct” PK and add FK’s to assist in reporting?

To head off the avalanch of “Don’t do it!!!” responses, let me make it clear that I am not going to do this to my production database, but copy of it on another server.

Any advice would be appreciated.

——- EDIT This is updated with correct information. —————-

Thanks guys, but I realized I’ve made a mistake. Almost every single table has an “identity_column” with the property of identity. That identity is a clustered index. However, it is not designated as a primary key.

First, what is the difference between a primary key and a clustered index?

Second, how can I script out all the clustered indexes?
Would this work?

SELECT 
  'ALTER TABLE ' + OBJECT_NAME(OBJECT_ID) + ' DROP CONSTRAINT ' + name 
FROM sys.indexes WHERE type_desc = 'CLUSTERED'

Thanks for your patience

Answer 1

How about something like this?

-- Helper Procedure 
CREATE PROC #DropConstraints 
  @tableSchema nvarchar(max), 
  @tableName nvarchar(max), 
  @constraintType nvarchar(20) 
AS 
BEGIN 
  DECLARE @cName nvarchar(max); 

  DECLARE constraint_cursor CURSOR FOR 
    SELECT CONSTRAINT_NAME  
    FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS 
    WHERE  
      CONSTRAINT_TYPE = @constraintType 
      AND TABLE_NAME = @tableName 
      AND TABLE_SCHEMA = @tableSchema 

  OPEN constraint_cursor 

  FETCH NEXT FROM constraint_cursor INTO @cName 
  WHILE @@FETCH_STATUS = 0 
  BEGIN 
    EXEC ('ALTER TABLE ' + @tableSchema + '.' + @tableName + ' DROP CONSTRAINT ' + @cName); 
    FETCH NEXT FROM constraint_cursor INTO @cName 
  END 

  CLOSE constraint_cursor 
  DEALLOCATE constraint_cursor 
END 
GO

BEGIN TRANSACTION

  -- Setup Cursor for looping 
  DECLARE table_cursor SCROLL CURSOR FOR 
    SELECT TABLE_SCHEMA, TABLE_NAME  
    FROM INFORMATION_SCHEMA.TABLES 

  OPEN table_cursor

  -- Declare Variables

  DECLARE 
    @tableSchema nvarchar(max), 
    @tableName nvarchar(max) 

 -- Drop Primary Keys 

  FETCH FIRST FROM table_cursor INTO @tableSchema, @tableName 
  WHILE @@FETCH_STATUS = 0 
  BEGIN 
    EXEC #DropConstraints @tableSchema, @tableName, 'PRIMARY KEY'; 

    FETCH NEXT FROM table_cursor INTO @tableSchema, @tableName 
  END 

  -- Cleanup 
  CLOSE table_cursor 
  DEALLOCATE table_cursor

COMMIT TRANSACTION 
GO

DROP PROCEDURE #DropConstraints;
GO