CASE expressions containing identical sub-queries that are executed in SQL Server 2017 may return incorrect results.
The fix for this issue is included in the following update for SQL Server:
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Each new build for SQL Server contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest build for your version of SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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