Sql queries for updating column values
The first approach that may come to mind is to add an identity column to your table if the table does not already have an identity column.
In addition to adding the column, I also need to populate the existing records with an incremental counter what options are there to do this?
In this step we are doing an UPDATE to the table and for each row that is updated we are updating the variable by 1 as well as the id column in the table.
This can be seen here (SET @id = id = @id 1) where we are making the @id value and the id column equal to the current @id value 1.
In this tip I will walk through the processes of encrypting a column in a table which contains credit card information of customers of XYZ company by using SQL Server symmetric key encryption.
SQL Server has an encryption hierarchy that needs to be followed in order to support the encryption capabilities.
If we compare the statistics time and statistics i/o from the the update with the identity column to this approach the overall number of logical reads is just about the same, but the overall duration is about 10 times faster doing the update versus having to maintain the identity value.