Operators

All mathematical operators (which is to say, all operators other than the concatenation operator ||) apply NUMERIC affinity to all operands prior to being carried out. If one or both operands cannot be converted to NUMERIC, then the result of the operation is NULL.

For the concatenation operator, TEXT affinity is applied to both operands. If either operand cannot be converted to TEXT (because it is NULL or a BLOB) then the result of the concatenation is NULL.