https://modern-sql.com/feature/is-distinct-from
In SQL NULL = NULL isn’t true. Use IS NOT DISTINCT FROM instead of equals (=) for null-aware comparisons.
comparison operatormodernsqldistinct
https://www.educba.com/c-sharp-or-operator/
Guide to C# OR Operator. Here we have discuss head to head comparison, a chart with statistics percentage, a table with all the C# operators.
coperatorheadtable