microsoft visual basic 2008 express edition registration key

In a typical SQL Data warehouse solution, it is often essential to maintain a history of data in the warehouse with a reference to the source data that is being fed to the ETL tool.

Although the MERGE statement is a little complex than the simple INSERTs or UPDATEs, once you are able to master the underlying concept, you can easily use this SQL MERGE more often than using the individual INSERTs or UPDATEs. The MERGE statement actually combines the INSERT, UPDATE, and the DELETE operations altogether. The MERGE statement tries to compare the source table with the target table based on a key field and then do some of the processing. As you can see, there are two circles that represent two tables and can be considered as Source and a Target. The above illustration depicts how a SQL MERGE statement basically works. The MERGE statement basically modifies an existing table based on the result of comparison between the key fields with another table in the context. Using the MERGE statement in SQL gives you better flexibility in customizing your complex SQL scripts and also enhances the readability of your scripts. You can specify conditions on which you expect the MERGE statement to insert, update, or delete, etc. MERGE statement in SQL is a very popular clause that can handle inserts, updates, and deletes all in a single transaction without having to write separate logic for each of these. In this article, I am going to give a detailed explanation of how to use the SQL MERGE statement in SQL Server.

Microsoft visual basic 2008 express edition registration key