You should use IS NOT NULL . (The comparison operators = and <> both give UNKNOWN with NULL on either side of the expression.) ... <看更多>

I should think a table-level CHECK constraint would serve here, something like. CONSTRAINT c1_c2_null_match CHECK ((c1 IS NULL AND c2 IS ... ... <看更多>

This may not be caused by LINQ2DB, but hopefully someone already came across this issue. I'm using LINQ2DB to access a MySQL instance ... ... <看更多>