SQL Simple Having
Today I will dicuss a way to filter your aggregated data, this is done by the use of a not so often used query keyword Having .
The whole solution can be viewed at this RexTester.
I say not so used because it is only maybe about 5% of the time that you will use this keyword, there are many other ways to achieve desired results such as CTE,Subquies and window functions.
Lets pretend we have a dataset such as this:
| ID | Name |
|---|---|
| 1 | Jim |
| 1 | Jim |
| 2 | Bob |
| 2 | Bob |
| 2 | Bob |
We simple want to know what name has 3 or more entries in the table.
We can apply a having clause to achieve this Having clause will go outside of the group by as an addition selectivity measure in our query.
SELECT [NAME], COUNT(*) AS RecordCount FROM #TEMP_A GROUP BY [NAME] HAVING COUNT(*) >= 3