Why Does Linq Generated Sql Include Multiple "is Null" Conditions For The Same Column

The following query against a SQL Server 2012 database, using Entity Framework Core 3.1: var tows = await _context.DataEntryTow .Where(t => _context.DataEntr

Solution 1:

Field MicroscopeId declared as nullable. So, to mimic LINQ to Objects behaviour when null != "0" is true but in SQL null <> '0' is false, EF Core generates additional OR condition.

To disable this geneeration you have to specify that when building DbContextOptions:

optionsBuilder.UseSqlServer(constr, b => b.UseRelationalNulls(true) );

Additional info: https://docs.microsoft.com/en-us/ef/core/querying/null-comparisons#using-relational-null-semantics