```
milovidov@milovidov-desktop:~/work/ClickHouse$ build/utils/db-generator/query_db_generator 
^C
milovidov@milovidov-desktop:~/work/ClickHouse$ build/utils/db-generator/query_db_generator --help
^C
milovidov@milovidov-desktop:~/work/ClickHouse$ build/utils/db-generator/query_db_generator < query.sql 
milovidov@milovidov-desktop:~/work/ClickHouse$ build/utils/db-generator/query_db_generator query.sql 
^C
```

{
public:
    std::string main_table;
    std::map<std::string, std::string> aliases;
    std::unordered_map<std::string, Table> tables;
    std::set<std::string> nested;
    bool tableExists(const std::string & table_name) const
    {
        return tables.count(table_name);
    }
    void addColumn(std::string full_column)