Hi @Anonymous ,
I wanna add some possible reasons that may make IntelliSense not work:
1.The local cache used by IntelliSense becomes stale. You can go to Edit -> IntelliSense -> Refresh Local Cache
2.This way maybe a little bit complicated but pls take some time to check if the IntelliSense was set as enabled:
Go to Tools -> Options -> Text Editor -> Transact-SQL -> General -> IntelliSense
Go to Query -> IntelliSense should be selected
Also verify that the T-SQL Editor does not launch in SQLCMD Mode. To check:
Go to Tools -> Options -> Query Execution -> SQL Server -> General
Make sure "By default, open new queries in SQLCMD mode" is unchecked.
or Go to Query -> SQLCMD Mode should not be selected
3.There is bug that VS2010 may cause this problem. Pls check this link: kb2531482-%E4%BF%AE%E5%A4%8D-%E5%AE%89%E8%A3%85-visual-studio-2010-sp1-%E5%90%8E-ssms-2008-r2-%E4%B8%AD%E7%9A%84%E6%99%BA%E8%83%BD%E6%84%9F%E7%9F%A5%E5%8A%9F%E8%83%BD%E5%8F%AF%E8%83%BD%E4%BC%9A%E5%81%9C%E6%AD%A2%E8%BF%90%E8%A1%8C-c4f0c486-918d-fc10-cbdb-587e20d0e355
4.Pls check this official link (some possbile reasons are shown on it) : https://learn.microsoft.com/en-us/previous-versions/visualstudio/visual-studio-2008/ks1ka3t6(v=vs.90)?redirectedfrom=MSDN
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