The python 4DBI
Project description
Python4DBI
In Memory Of Edson de Sousa (14/04/94 - 16/08/18), i will see you again
Table of contents
General info
- 4D is an incredibly productive development platform that lets you focus on your data model and your business rules.
- The 4D framework takes care of running your application code natively on macOS and Windows.
- The 4DBI is written in pure python and allows a python program to use SQL to access one or more databases from a single application without using the 4D ODBC driver.
- 4D and 4D Server both provide a native SQL server that enables this functionality.
Technologies
Project is created with:
- Python
- texttable - https://github.com/foutaise/texttable/
Setup
To run this project, install it locally using pip:
$ pip install python4DBI
API
Cursor
It consists of pure application logic, which interacts with the database. It includes all the information to represent data to the end user.
Properties
row_number
Return: int or None
This read-only attribute provides the current 0-based index of the cursor in the result set or None if the index cannot be determined
row_count
Return: int
This read-only attribute specifies the number of rows that the last .execute*()
description
Return: List
A Cursor object's description attribute returns information about each of the result columns of a query.
Methods
close
Return: None
Close the current 4D SQL server cursor
prepare_statement
Params: query ( str )
Return: int
Checks if the statement is valid should always be execute before an execute statement returns FOURD_OK or FOURD_ERROR
set_input_sizes
Not implemented!
Params: size ( int )
Return: None
This can be used before a call to .execute*() to predefine memory areas for the operation's parameters.
set_output_size
Not implemented!
Params: size ( int )
Return: None
Set a column buffer size for fetches of large columns (e.g. LONGs, BLOBs, etc.). the column is specified as an index into the result sequence. Not specifying the column will set the default size for all large columns in the cursor.
execute
Params: query (str), params (dict), page_size (int), on_before_execute (funtion), on_executed (funtion), *args, **kwargs
Return: None
Prepare and execute a database operation (query or command).
fetch_one
Return: List or None
Fetch the next row of a query result set, returning a single sequence, or None when no more data is available.
fetch_many
Params: size (int)
Return: Two-dimensional List or None
Fetch the next set of rows of a query result, returning a sequence of sequences (e.g. a list of tuples). An empty sequence is returned when no more rows are available.
fetch_all
Return: Two-dimensional List or None
Fetch all (remaining) rows of a query result. Note that the cursor's array size attribute can affect the performance of this operation.
start_transaction
Return: None
Opens a transaction
cancel_transaction
Return: None
Rollback an open transaction Same operation as rollback method
rollback
Return: None
Rollback an open transaction Same operation as cancel_transaction method
commit
Return: None
Commits an open transaction Same operation as validate_transaction method
validate_transaction
Return: None
Commits an open transaction Same operation as commit method
send_messages_in_base_64
Params: use_b64 (bool)
Return: None
Sets the base 64 mode
set_protocol_version
Params: protocol_version (str)
Return: None
Sets the 4D SQL server protocol version
set_preferred_image_types
Params: preferred_image_types (str)
Return: None
Sets the preferred image type
Currently only supports 'png' pr 'jpg' formats
use_debug
Params: debug (bool)
Return: None
Sets the debug mode
set_fmt
Params: fmt (str)
Return: None
print_result
Params: headers (List), rows (List), max_width (int)
Return: None
Prints a 4D SQL server cursor result
Sets the type of binary architecture
Currently supports the following formats:
'<' little-endian for MAC OS X - RVLB
'>' big-endian for Windows - BLVR
Database Interface
It acts as an intermediary between view and model
Methods
connect
Params: ** kwargs
Return: None
Opens a socket connection to the 4D SQL Server
kwargs supported are:
- socket_timeout : int (default 10)
- dsn : str (default '')
- host : str (default '127.0.0.1')
- port : int (default 19812)
- user : str (default '')
- password : str (default '')
close
Return: None
Closes the current 4D SQL server socket connection
cursor
Return: _python4DCursor object
Returns a 4D SQL server cursor object
connected
Return: bool
Returns true if the socket is connected to the 4D SQL server and false otherwise
get_socket
Return: self._socket object
Returns the current socket object
get_socket_timeout
Return: int
Returns the current socket timeout
get_host
Return: str
Returns the current to 4D SQL server host
get_port
Return: int
Returns the current to 4D SQL server port
get_user
Return: str
Returns the current to 4D SQL server user
get_password
Return: str
Returns the current to 4D SQL server password
View
It represents the model’s data to user.
Methods
print_result
Params: headers (List), rows (List), max_width (int)
Return: None
Prints a 4D SQL server cursor result 4D SQL server header description is a list of tuples [(str, obj)], so print_result is expecting to a list in that format as header
Example
import time
from python4DBI.python4DBI import python4DBI
con = python4DBI()
con.connect(user='theUser', password='thePassword')
cursor = con.cursor()
t0 = time.time()
cursor.execute(query='SELECT * FROM EMPLOYEES')
if cursor.row_count > 0:
result = cursor.fetch_all()
con.print_result(headers=cursor.description, rows=result)
t1 = time.time()
total = t1-t0
+------------+--------+----------+----------+----------+----------+----------+----------+-----------+------+---------+-----------+--------+-------+-------+------+
| EmployeeID | Last | Name | First | Name | Address1 | Address2 | Zip | Code | City | Country | Telephone | Mobile | Phone | Birth | Date |
+------------+--------+----------+----------+----------+----------+----------+----------+-----------+------+---------+-----------+--------+-------+-------+------+
| 1 | Barros | Marciano | Address1 | Address2 | 9000 | FUNCHAL | Portugal | 3.510e+09 | | None | | None | None | | |
+------------+--------+----------+----------+----------+----------+----------+----------+-----------+------+---------+-----------+--------+-------+-------+------+
Execution time : 0.022388219833374023
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
