Int dtypes are unnecessarily big #688
Description
What language are you using?
Python
What version are you using?
0.3.3
What database are you using?
MySQL
What dataframe are you using?
Polars
Can you describe your bug?
Connectorx pointlessly transforms smaller db dtypes into int64, leading to higher memory usage.
See mysql mappings or MSSQL mappings
What are the steps to reproduce the behavior?
Perform a query to mysql using connectorx to a table containing a smaller dtype in a column.
The df will have int64 dtypes in all numeric dtypes, as specified by the incorrect transports linked above.
For example with polars which respectes the dtypes provided by connectorx:
import polars as pl
mysql_uri = f'{mysql_db_type}://{mysql_username}:{mysql_password}@{mysql_host}:{mysql_port}/{mysql_database_name}'
test_dataset = pl.read_database_uri(query, self.mysql_uri)
What is the error?
There will be no error message, just incorret dtypes.