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Using Results from one column to calculate another column


Using Results from one column to calculate another column

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ChrisM@Work
ChrisM@Work
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ScottPletcher (1/7/2013)
If all the columns are from a single table, you definitely should created a computed column that has the computation: that way, the definition is in only one place. ...[/code]


+1

Otherwise, use CROSS APPLY, keeping the definition in only one place in the query. If the calculation is used in many queries, consider constructing an inline "row-valued" function.

“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw

For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden
Exploring Recursive CTEs by Example Dwain Camps
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