**Usage**
Postgres, MySQL, and Oracle support the expression `LEFT JOIN ... ON 1 = 1`, but ClickHouse does not.

It may be possible to replace `LEFT JOIN ... ON 1 = 1` with `CROSS JOIN`, but I want to use the query in the same form for lots of databases.

Please support the expression `LEFT JOIN ... ON 1 = 1`.


**Detailed SQL**
```SQL
CREATE TABLE test
(
    `name` Nullable(String),
    `id` int
)
ENGINE = Log();

insert into test values ('a', 1) ('b', 2) (null, 3);

select * from test t1 left join (select * from test ) t2 on 1 = 1   
-- DB::Exception: Not equi-join ON expression: 1 = 1. No columns in one of equality side.: While processing 1 = 1.
```

{
    if constexpr (is_asof_join)
    {
        auto key_column_copy = key_columns;
        auto key_size_copy = key_sizes;
        key_column_copy.pop_back();
        key_size_copy.pop_back();
        return KeyGetter(key_column_copy, key_size_copy, nullptr);
    }
    else
        return KeyGetter(key_columns, key_sizes, nullptr);
}
template <typename Mapped, bool need_offset = false>
using FindResultImpl = ColumnsHashing::columns_hashing_impl::FindResultImpl<Mapped, true>;
class KeyGetterForDict
{
public:
    using Mapped = RowRef;
    using FindResult = FindResultImpl<Mapped, true>;
    KeyGetterForDict(const TableJoin & table_join, const ColumnRawPtrs & key_columns)
    {
        assert(table_join.getDictionaryReader());
        table_join.getDictionaryReader()->readKeys(*key_columns[0], read_result, found, positions);
        for (ColumnWithTypeAndName & column : read_result)
            if (table_join.rightBecomeNullable(column.type))
                JoinCommon::convertColumnToNullable(column);
    }
    FindResult findKey(const TableJoin &, size_t row, const Arena &)