Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Please help explain create table syntax and reason for each line

Posted on 2012-12-28
2
Medium Priority
?
228 Views
Last Modified: 2012-12-28
Please explain why each line of code exists in this script.

I am not a very experienced T-SQL programmer.

Thank you,

Tom





USE [PP]
GO

IF  EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_ProductMatrix_ProductType]') AND parent_object_id = OBJECT_ID(N'[dbo].[ProductMatrix]'))
ALTER TABLE [dbo].[ProductMatrix] DROP CONSTRAINT [FK_ProductMatrix_ProductType]
GO

IF  EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_ProductMatrix_Task]') AND parent_object_id = OBJECT_ID(N'[dbo].[ProductMatrix]'))
ALTER TABLE [dbo].[ProductMatrix] DROP CONSTRAINT [FK_ProductMatrix_Task]
GO

IF  EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_ProductMatrix_TaskWorkFlow]') AND parent_object_id = OBJECT_ID(N'[dbo].[ProductMatrix]'))
ALTER TABLE [dbo].[ProductMatrix] DROP CONSTRAINT [FK_ProductMatrix_TaskWorkFlow]
GO

IF  EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID(N'[DF_ProductMatrix_ProductMatrixSID]') AND type = 'D')
BEGIN
ALTER TABLE [dbo].[ProductMatrix] DROP CONSTRAINT [DF_ProductMatrix_ProductMatrixSID]
END

GO

USE [PP]
GO

/****** Object:  Table [dbo].[ProductMatrix]    Script Date: 11/16/2012 10:52:09 ******/
IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ProductMatrix]') AND type in (N'U'))
DROP TABLE [dbo].[ProductMatrix]
GO

USE [PP]
GO

/****** Object:  Table [dbo].[ProductMatrix]    Script Date: 11/16/2012 10:52:09 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[ProductMatrix](
	[ProductMatrixID] [int] IDENTITY(1,1) NOT NULL,
	[ProductMatrixSID] [int] NOT NULL,
	[TaskWorkFlowID] [int] NULL,
	[TaskWorkFlowSID] [int] NULL,
	[IDTemplate] [int] NULL,
	[TaskID] [int] NULL,
	[NewProductID] [int] NULL,
 CONSTRAINT [PK_ProductMatrix] PRIMARY KEY CLUSTERED 
(
	[ProductMatrixID] ASC,
	[ProductMatrixSID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON, FILLFACTOR = 85) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[ProductMatrix]  WITH CHECK ADD  CONSTRAINT [FK_ProductMatrix_ProductType] FOREIGN KEY([NewProductID])
REFERENCES [dbo].[ProductType] ([ProductTypeID])
GO

ALTER TABLE [dbo].[ProductMatrix] CHECK CONSTRAINT [FK_ProductMatrix_ProductType]
GO

ALTER TABLE [dbo].[ProductMatrix]  WITH CHECK ADD  CONSTRAINT [FK_ProductMatrix_Task] FOREIGN KEY([TaskID])
REFERENCES [dbo].[Task] ([TaskID])
GO

ALTER TABLE [dbo].[ProductMatrix] CHECK CONSTRAINT [FK_ProductMatrix_Task]
GO

ALTER TABLE [dbo].[ProductMatrix]  WITH CHECK ADD  CONSTRAINT [FK_ProductMatrix_TaskWorkFlow] FOREIGN KEY([TaskWorkFlowID], [TaskWorkFlowSID])
REFERENCES [dbo].[TaskWorkFlow] ([TaskWorkFlowID], [TaskWorkFlowSID])
GO

ALTER TABLE [dbo].[ProductMatrix] CHECK CONSTRAINT [FK_ProductMatrix_TaskWorkFlow]
GO

ALTER TABLE [dbo].[ProductMatrix] ADD  CONSTRAINT [DF_ProductMatrix_ProductMatrixSID]  DEFAULT (right(@@servername,(1))) FOR [ProductMatrixSID]
GO


USE [pp]
GO

ALTER TABLE [dbo].ProductMatrix ADD  CONSTRAINT [UK_ProductMatrix_All] UNIQUE NONCLUSTERED 
(
	[ProductMatrixID] ,
	[ProductMatrixSID] ,
	[TaskWorkFlowID] ,
	[TaskWorkFlowSID] ,
	[IDTemplate],
	[TaskID] ,
	[NewProductID]
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON, FILLFACTOR = 85) ON [PRIMARY]
GO

Open in new window

0
Comment
Question by:Tom Knowlton
2 Comments
 
LVL 18

Accepted Solution

by:
Jerry Miller earned 2000 total points
ID: 38728277
--Lines 4-20 are looking for the existence of Foreign Key constraints and dropping them if they exists. The table cannot be dropped as long as these constraints are in place

--Lines 29-32 are checking for the existence of the current table and dropping it if it is there

--the rest of the lines are creating the table with the necessary foreign key constraints that were dropped earlier

It is generally good practice to check for the existence of an object before dropping it so that the stored procedure doesn't error if it is not there. Dropping the objects avoids errors generated upon the creation in the second half of the procedure.
0
 
LVL 5

Author Closing Comment

by:Tom Knowlton
ID: 38728304
B - E - A utiful  !!!

: )
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Long way back, we had to take help from third party tools in order to encrypt and decrypt data.  Gradually Microsoft understood the need for this feature and started to implement it by building functionality into SQL Server. Finally, with SQL 2008, …
This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
This video shows how to quickly and easily deploy an email signature for all users in Office 365 and prevent it from being added to replies and forwards. (the resulting signature is applied on the server level in Exchange Online) The email signat…
Integration Management Part 2

782 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question