When I use a null coalescing operator in the “.Where” section of a linq statement, it’s not working as intended.

Here’s the offending code: (Note that the TotalBalance is of type nullable decimal.)

Account.Where(n => (n.TotalBalance ?? 0) != 0)
.Select(n => new { n.AccountId, n.TotalBalance })

The result includes accounts whose TotalBalance is null:

Checking the SQL generated by LINQ to SQL, I can see the problem:

SELECT [n].[AccountID], [n].[TotalBalance]
FROM [Account] AS [n]
WHERE (COALESCE([n].[TotalBalance], 0.0) <> 0.0) OR [n].[TotalBalance] IS NULL

Why is LINQ to SQL inserting the condition OR [n].[TotalBalance] IS NULL?

If I remove the null coalesce from the linq statement, the results are correct:

Account.Where(n=>n.TotalBalance != null && n.TotalBalance != 0)
.Select(n => new { n.AccountId, n.TotalBalance })

Using EF Core version 2.2.6 (yes, I know it’s deprecated. Is that a known bug that was fixed?)