Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
Solved

# binary checksum or checksum table

Posted on 2006-11-15
Medium Priority
1,282 Views
Hi
What is binary checksum or checksum table and where can we use this.

Thanks
0
Question by:atwork2003
[X]
###### Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

• Help others & share knowledge
• Earn cash & points
1 Comment

LVL 75

Accepted Solution

Aneesh Retnakaran earned 2000 total points
ID: 17948441
Did u  check books online, there are few exampples given

A. Use BINARY_CHECKSUM to detect changes in the rows of a table.
This example uses BINARY_CHECKSUM to detect changes in a row of the Products table in the Northwind database.

/*Get the checksum value before the values in the specific rows (#13-15) are changed.*/
USE   Northwind
GO
CREATE   TABLE TableBC (ProductID int, bchecksum int)
INSERT   INTO TableBC
SELECT   ProductID, BINARY_CHECKSUM(*)
FROM      Products
/*TableBC contains a column of 77 checksum values corresponding to each row in the Products table.*/

--A large company bought products 13-15.
--The new company modified the products names and unit prices.
--Change the values of ProductsName and UnitPrice for rows 13, 14, and 15 of the Products table.*/
UPDATE   Products
SET   ProductName='Oishi Konbu', UnitPrice=5
WHERE   ProductName='Konbu'

UPDATE   Products
SET   ProductName='Oishi Tofu', UnitPrice=20
WHERE   ProductName='Tofu'

UPDATE   Products
SET   ProductName='Oishi Genen Shouyu', UnitPrice=12
WHERE   ProductName='Genen Shouyu'

--Determine the rows that have changed.
SELECT   ProductID
FROM      TableBC
WHERE   EXISTS   (
SELECT   ProductID
FROM      Products
WHERE      Products.ProductID = TableBC.ProductID
AND   BINARY_CHECKSUM(*) <> TableBC.bchecksum)

Here is the result set:

ProductID
13
14
15

0

## Featured Post

Question has a verified solution.

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

In part one, we reviewed the prerequisites required for installing SQL Server vNext. In this part we will explore how to install Microsoft's SQL Server on Ubuntu 16.04.
When trying to connect from SSMS v17.x to a SQL Server Integration Services 2016 instance or previous version, you get the error “Connecting to the Integration Services service on the computer failed with the following error: 'The specified service …
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables. Make a table: Update a specific column given a specific row using the UPDATE statement: Remove a set of values using the DELETE s…
###### Suggested Courses
Course of the Month7 days, 6 hours left to enroll