# Copyright 2021 The SQLNet Company GmbH
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
"""
Creates a new ODBC database connection.
"""
import getml.communication as comm
import getml.constants as constants
from .connection import Connection
[docs]def connect_odbc(
server_name,
user="",
password="",
escape_chars='"',
double_precision="DOUBLE PRECISION",
integer="INTEGER",
text="TEXT",
time_formats=None,
conn_id="default",
):
"""
Creates a new ODBC database connection.
ODBC is standardized format that can be used to connect to almost any
database.
Before you use the ODBC connector, make sure the database is up and
running and that the appropriate ODBC drivers are installed.
Args:
server_name (str):
The server name, as referenced in your .obdc.ini file.
user (str, optional):
User name with which to log into the database.
You do not need to pass this, if it is already contained in your
.odbc.ini.
password (str, optional):
Password with which to log into the database.
You do not need to pass this, if it is already contained in your
.odbc.ini.
escape_chars (str, optional):
ODBC drivers are supposed to support
escaping table and column names using '"' characters irrespective of the
syntax in the target database. Unfortunately, not all ODBC drivers
follow this standard. This is why some
tuning might be necessary.
The escape_chars value behaves as follows:
* If you pass an empty string, schema, table and column names will not
be escaped at all. This is not a problem unless some table
or column names are identical to SQL keywords.
* If you pass a single character, schema, table and column names will
be enveloped in that character: "TABLE_NAME"."COLUMN_NAME" (standard SQL)
or `TABLE_NAME`.`COLUMN_NAME` (MySQL/MariaDB style).
* If you pass two characters, table, column and schema names will be
enveloped between these to characters. For instance, if you pass "[]",
the produced queries look as follows:
[TABLE_NAME].[COLUMN_NAME] (MS SQL Server style).
* If you pass more than two characters, the engine will throw an exception.
double_precision (str, optional):
The keyword used for double precision columns.
integer (str, optional):
The keyword used for integer columns.
text (str, optional):
The keyword used for text columns.
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.
Note:
By selecting an existing table of your database in
:func:`~getml.DataFrame.from_db` function, you can create
a new :class:`~getml.DataFrame` containing all its data.
Alternatively you can use the
:meth:`~.getml.DataFrame.read_db` and
:meth:`~.getml.DataFrame.read_query` methods to replace
the content of the current :class:`~getml.DataFrame`
instance or append further rows based on either a table or a
specific query.
You can also write your results back into the
database. By passing the name for the destination table to
:meth:`getml.Pipeline.transform`, the features
generated from your raw data will be written back. Passing
them into :meth:`getml.Pipeline.predict`, instead,
makes predictions of the target variables to new, unseen data
and stores the result into the corresponding table.
"""
# -------------------------------------------
time_formats = time_formats or constants.TIME_FORMATS
# -------------------------------------------
# Prepare command.
cmd = dict()
cmd["name_"] = ""
cmd["type_"] = "Database.new"
cmd["db_"] = "odbc"
cmd["server_name_"] = server_name
cmd["user_"] = user
cmd["escape_chars_"] = escape_chars
cmd["double_precision_"] = double_precision
cmd["integer_"] = integer
cmd["text_"] = text
cmd["time_formats_"] = time_formats
cmd["conn_id_"] = conn_id
# -------------------------------------------
# Send JSON command to engine.
sock = comm.send_and_get_socket(cmd)
# -------------------------------------------
# The password is sent separately, so it doesn't
# end up in the logs.
comm.send_string(sock, password)
# -------------------------------------------
# Make sure that everything went well.
msg = comm.recv_string(sock)
if msg != "Success!":
comm.engine_exception_handler(msg)
# -------------------------------------------
return Connection(conn_id=conn_id)