how to alter table Composite primary key

Question

CREATE TABLE [dbo].[INVS_ITEM_LOCATIONS]
([DEPARTMENT_CODE] [varchar](3) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
 [IM_INV_NO] [numeric](10, 0) NOT NULL,
 [LOCATION_CODE] [varchar](2) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
 [CURR_QTY] [numeric](10, 0) NOT NULL CONSTRAINT [DF__INVS_ITEM__CURR___1352D76D]  DEFAULT ((0)),
 [DO_QTY] [numeric](10, 0) NOT NULL CONSTRAINT [DF__INVS_ITEM__DO_QT__1446FBA6]  DEFAULT ((0)),
 [ALLOC_QTY] [numeric](10, 0) NOT NULL CONSTRAINT [DF__INVS_ITEM__ALLOC__153B1FDF]  DEFAULT ((0)),
 [YOB_QTY] [numeric](10, 0) NOT NULL CONSTRAINT [DF__INVS_ITEM__YOB_Q__162F4418]  DEFAULT ((0)),
 [FOC_QTY] [numeric](10, 0) NULL CONSTRAINT [DF__INVS_ITEM__FOC_Q__17236851]  DEFAULT ((0)),
 [USER_CREATED] [varchar](25) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
 [DATE_CREATED] [datetime] NOT NULL,
 [USER_MODIFIED] [varchar](25) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
 [DATE_MODIFIED] [datetime] NULL,

 CONSTRAINT [INVS_ITEM_LOCATIONS_PK] 
 PRIMARY KEY CLUSTERED ([DEPARTMENT_CODE] ASC,
 [IM_INV_NO] ASC, [LOCATION_CODE] ASC)
 WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

This is my table structure ......how can I remove the composite primary key in table and also I should add foreign key to im_inv_no reference table is invs_location which contain im_inv_no and the department_code should be same primary key .pls help

Answer 1

You can create new tables with modifications you need, copy your data then renaming new talbes to the same names as old tables and deleting old ones. It is probably the most efficient way as well.

Answer 2

To remove your composite primary key, use:

ALTER TABLE dbo.INVS_ITEM_LOCATIONS
  DROP CONSTRAINT INVS_ITEM_LOCATIONS_PK

To add a foreign key, use this:

ALTER TABLE dbo.INVS_ITEM_LOCATIONS
  ADD CONSTRAINT FK_INV_NO_REFERENCE
  FOREIGN KEY(IM_INV_NO, DEPARTMENT_CODE)
  REFERENCES dbo.invs_location(IM_INV_NO, DEPARTMENT_CODE)

These are all really basic beginner SQL questions - I would strongly recommend you read one of the various good SQL tutorials out there to get used to SQL first, before posting each and every single little question here....

W3Schools SQL Tutorial

Marc