I use an expression as `update_field` because this feature is not implemented yet: https://github.com/ClickHouse/ClickHouse/issues/6084

20.5 generates an incorrect query in this case:
```WHERE `date_add(updated_date, interval 15 minute)` >= '2020-07-02 16:40:06'```

The exception:
```mysqlxx::BadQuery: Unknown column 'date_add(updated_date, interval 15 minute)' in 'where clause'```

The problem is here: 
https://github.com/ClickHouse/ClickHouse/blob/b81c66a03148afc02647df3c11aec40382329912/src/Dictionaries/ExternalQueryBuilder.cpp#L172
The change was introduced in this PR: https://github.com/ClickHouse/ClickHouse/pull/11079

size_t beg, size_t end) const
{
    auto first = true;
    for (const auto i : ext::range(beg, end))
    {
        if (!first)
            writeString(" AND ", out);
        first = false;
        const auto & key_description = (*dict_struct.key)[i];
        
        writeQuoted(key_description.name, out);
        writeString("=", out);
        key_description.type->serializeAsTextQuoted(*key_columns[i], row, out, format_settings);
    }
}
void ExternalQueryBuilder::composeInWithTuples(const Columns & key_columns, const std::vector<size_t> & requested_rows,