Method executeImpl

src/Functions/nullIf.cpp:47–65

    }

    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
    {
        /// nullIf(col1, col2) == if(col1 = col2, NULL, col1)

        auto equals_func = FunctionFactory::instance().get("equals", context)->build(arguments);
        auto eq_res = equals_func->execute(arguments, equals_func->getResultType(), input_rows_count);

        ColumnsWithTypeAndName if_columns
        {
            {eq_res, equals_func->getResultType(), ""},
            {result_type->createColumnConstWithDefaultValue(input_rows_count), result_type, "NULL"},
            arguments[0],
        };

        auto func_if = FunctionFactory::instance().get("if", context)->build(if_columns);
        auto if_res = func_if->execute(if_columns, result_type, input_rows_count);

        return makeNullable(std::move(if_res));
    }
};

}