Storing Computed Columns in SQL Server
From time to time you will run into a case where you need to store computed columns in your SQL Server tables. Examples of computed columns include taxes on a sale or business days between several dates. Setting up computed columns in SQL Server 2008 is fairly simple. You simply give the column a name and then specify your calculation instead of giving a datatype. You could even use a case statement instead of functions and calculations. Here is an example of a table that calculates days between 2 dates.
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<span style="color: #0000ff;">CREATE TABLE</span> dbo.DateDiffTable ( RowID <span style="color: #0000ff;">int</span> NOT NULL <span style="color: #0000ff;">IDENTITY</span> (1, 1), DateStart <span style="color: #0000ff;">smalldatetime</span> NOT NULL, DateFinish <span style="color: #0000ff;">smalldatetime</span> NOT NULL, DateDiffs <span style="color: #0000ff;">AS</span> <span style="color: #ff00ff;">datediff</span>(DD,DateStart,DateFinish) NOT NULL ) <span style="color: #0000ff;">GO</span> |
The sample table has an ID, 2 dates and … Continue reading Storing Computed Columns in SQL Server
