CODEWITHSUNDEEP
pythonmysqlpandassqlalchemy
HackToHell
HackToHell

Reputation: 2393

Specifying the schema in Pandas to_sql

From the source of to_sql, I can see that it gets mapped to an Meta Data object meta = MetaData(con, schema=schema). However, I can't find SQLAlchemy docs that tell me how to define the Schema for MySQL

How do I specify the schema string ?

Upvotes: 40

Views: 44672

Answers (3)

Vasin Yuriy
Vasin Yuriy

Reputation: 535

DataFrame.to_sql(self, name, con, schema=None, if_exists='fail', index=True, index_label=None, chunksize=None, dtype=None, method=None)

Just use schema parameter. But note that schema is not odbc driver.

Upvotes: 2

Eilif Mikkelsen
Eilif Mikkelsen

Reputation: 336

The schema parameter in to_sql is confusing as the word "schema" means something different from the general meaning of "table definitions". In some SQL flavors, notably postgresql, a schema is effectively a namespace for a set of tables.

For example, you might have two schemas, one called test and one called prod. Each might contain a table called user_rankings generated in pandas and written using the to_sql command. You would specify the test schema when working on improvements to user rankings. When you are ready to deploy the new rankings, you would write to the prod schema.

As others have mentioned, when you call to_sql the table definition is generated from the type information for each column in the dataframe. If the table already exists in the database with exactly the same structure, you can use the append option to add new data to the table.

Upvotes: 13

van
van

Reputation: 76982

Starting from the Dialects page of the SQLAlchemy documentation, select documentation page of your dialect and search for create_engine to find example on how to create it.

Even more concise overview you can get on Engine Configuration page for all supported dialects.

Verbatim extract for mysql:

# default
engine = create_engine('mysql://scott:tiger@localhost/foo')

# mysql-python
engine = create_engine('mysql+mysqldb://scott:tiger@localhost/foo')

# MySQL-connector-python
engine = create_engine('mysql+mysqlconnector://scott:tiger@localhost/foo')

# OurSQL
engine = create_engine('mysql+oursql://scott:tiger@localhost/foo')

Then pass this engine to the to_sql(...) of pandas' DataFrame.

Upvotes: -8

Related Questions