21.5.1
```sql

create table test(d Date, k Int64, s String) 
Engine=MergeTree partition by (toYYYYMM(d),k) order by (d, k)

insert into test values ('2020-01-01', 1, '');
insert into test values ('2020-01-02', 1, '');

SELECT * FROM test WHERE d != '2020-01-01'
0 rows in set. Elapsed: 0.003 sec.


SELECT * FROM test WHERE identity(d) !=  '2020-01-01';
┌──────────d─┬─k─┬─s─┐
│ 2020-01-02 │ 1 │   │
└────────────┴───┴───┘

SELECT * FROM test WHERE toDate(d) != '2020-01-01';
┌──────────d─┬─k─┬─s─┐
│ 2020-01-02 │ 1 │   │
└────────────┴───┴───┘
```

const FunctionBasePtr & func,
    const DataTypePtr & arg_type,
    const Field & arg_value)
{
    ColumnsWithTypeAndName columns
    {
        { arg_type->createColumnConst(1, arg_value), arg_type, "x" },
    };
    auto col = func->execute(columns, func->getResultType(), 1);
    return (*col)[0];
}
static std::pair<Field, DataTypePtr> applyFunctionForFieldOfUnknownType(