That data should be accurate, private, and protected from damage. It should be accurate so that diverse applications with different data requirements can employ the data. Different application programmers and various end-users have different views upon data, which must be derived from a common overall data structure. Their methods of searching and accessing of data will be different.

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I have been told these types of operations are what SQL Server is designed to process and it should be quicker than serial processing. I know cursors exist but I am not sure how to use them. Can you provide some cursor examples? Can you give any guidance on when to use cursors? I assume Microsoft included them in SQL Server for a reason so they must have a place where they can be used in an efficient manner.

Solution In some circles, cursors are never used. In others, they are a last resort. And in other groups they are used regularly. In each of these camps, they have different reasons for their stand on cursor usage. Regardless, they probably have a place in particular circumstances and not in others. It boils down to your understanding of the coding technique then your understanding of the problem at hand to make a decision on whether or not cursor-based processing is appropriate or not.

The purpose for the cursor may be to update one row at a time or perform an administrative process such as SQL Server database backups in a sequential manner. Once you learn the steps you are easily able to duplicate them with various sets of logic to loop through data. This logic would be updated based on your needs.

Declare cursor with a specific name i. The cursor name can be anything meaningful. This is immediately followed by opening the cursor. Fetch a record from cursor to begin the data processing. In the example in this tip there is only one variable, one column selected and variable fetched, but if five pieces of data were needed for the cursor then five variables would need to be selected and fetched as well.

The data process is unique to each set of logic. This could be inserting, updating, deleting, etc. This is the most important set of logic during this process that is performed on each row. Fetch the next record from cursor as you did in step 3 and then step 4 is repeated again by processing the selected data. Once all of the data has been processed, then you close cursor. As a final and important step, you need to deallocate the cursor to release all of the internal resources SQL Server is holding.

From here, check out the examples below to get started on knowing when to use SQL Server cursors and how to do so. This could be 1 or many variables and associated columns.


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