connect_postgres(dbname, user, password, host, hostaddr, port=5432, time_formats=None, conn_id='default')¶
Creates a new PostgreSQL database connection.
But first, make sure your database is running and you can reach it from via your command line.
dbname (str): The name of the database to which you want to connect. user (str): User name with which to log into the PostgreSQL database. password (str): Password with which to log into the PostgreSQL database. host (str): Host of the PostgreSQL database. hostaddr (str): IP address of the PostgreSQL database. port(int, optional): Port of the PostgreSQL database.
The default port used by PostgreSQL is 5432.
If you do not know, which port to use, type the following into your PostgreSQL client
SELECT setting FROM pg_settings WHERE name = 'port';
time_formats (List[str], optional):
The list of formats tried when parsing time stamps.
The formats are allowed to contain the following special characters:
%w - abbreviated weekday (Mon, Tue, …)
%W - full weekday (Monday, Tuesday, …)
%b - abbreviated month (Jan, Feb, …)
%B - full month (January, February, …)
%d - zero-padded day of month (01 .. 31)
%e - day of month (1 .. 31)
%f - space-padded day of month ( 1 .. 31)
%m - zero-padded month (01 .. 12)
%n - month (1 .. 12)
%o - space-padded month ( 1 .. 12)
%y - year without century (70)
%Y - year with century (1970)
%H - hour (00 .. 23)
%h - hour (00 .. 12)
%a - am/pm
%A - AM/PM
%M - minute (00 .. 59)
%S - second (00 .. 59)
%s - seconds and microseconds (equivalent to %S.%F)
%i - millisecond (000 .. 999)
%c - centisecond (0 .. 9)
%F - fractional seconds/microseconds (000000 - 999999)
%z - time zone differential in ISO 8601 format (Z or +NN.NN)
%Z - time zone differential in RFC format (GMT or +NNNN)
%% - percent sign
- conn_id (str, optional): The name to be used to reference the connection.
If you do not pass anything, this will create a new default connection.
By selecting an existing table of your database in
from_db()function, you can create a new
DataFramecontaining all its data. Alternatively you can use the
read_query()methods to replace the content of the current
DataFrameinstance or append further rows based on either a table or a specific query.
You can also write your results back into the PostgreSQL database. By passing the name for the destination table to
getml.pipeline.Pipeline.transform(), the features generated from your raw data will be written back. Passing them into
getml.pipeline.Pipeline.predict(), instead, makes predictions of the target variables to new, unseen data and stores the result into the corresponding table.