Function evalComparison

pkg/sql/sem/tree/eval.go:4527–4538

(ctx *EvalContext, op ComparisonOperator, left, right Datum)

}

func evalComparison(ctx *EvalContext, op ComparisonOperator, left, right Datum) (Datum, error) {
	if left == DNull || right == DNull {
		return DNull, nil
	}
	ltype := left.ResolvedType()
	rtype := right.ResolvedType()
	if fn, ok := CmpOps[op].LookupImpl(ltype, rtype); ok {
		return fn.Fn(ctx, left, right)
	}
	return nil, pgerror.Newf(
		pgcode.UndefinedFunction, "unsupported comparison operator: <%s> %s <%s>", ltype, op, rtype)
}

// foldComparisonExpr folds a given comparison operation and its expressions
// into an equivalent operation that will hit in the CmpOps map, returning