zilian-mssql-django 1.1.4

Django backend for Microsoft SQL Server

SQL Server backend for Django

Welcome to the Zilian-MSSQL-Django 3rd party backend project!

zilian-mssql-django is a fork of mssql-django. This project provides an enterprise database connectivity option for the Django Web Framework, with support for Microsoft SQL Server and Azure SQL Database.

We'd like to give thanks to the community that made this project possible, with particular recognition of the contributors: OskarPersson, michiya, dlo and the original Google Code django-pyodbc team. Moving forward we encourage partipation in this project from both old and new contributors!

We hope you enjoy using the Zilian-MSSQL-Django 3rd party backend.

Features

• Supports Django 3.2 and 4.0
• Tested on Microsoft SQL Server 2016, 2017, 2019
• Passes most of the tests of the Django test suite
• Compatible with Micosoft ODBC Driver for SQL Server, SQL Server Native Client, and FreeTDS ODBC drivers
• Supports AzureSQL serveless db reconnection

Dependencies

• pyodbc 3.0 or newer

Installation

1. Install pyodbc 3.0 (or newer) and Django

2. Install zilian-mssql-django:

   pip install zilian-mssql-django
   

3. Set the ENGINE setting in the settings.py file used by your Django application or project to 'mssql':

   'ENGINE': 'mssql'
   

Configuration

Standard Django settings

The following entries in a database-level settings dictionary in DATABASES control the behavior of the backend:

• ENGINE

  String. It must be "mssql".

• NAME

  String. Database name. Required.

• HOST

  String. SQL Server instance in "server\instance" format.

• PORT

  String. Server instance port. An empty string means the default port.

• USER

  String. Database user name in "user" format. If not given then MS Integrated Security will be used.

• PASSWORD

  String. Database user password.

• TOKEN

  String. Access token fetched as a user or service principal which has access to the database. E.g. when using azure.identity, the result of DefaultAzureCredential().get_token('https://database.windows.net/.default') can be passed.

• AUTOCOMMIT

  Boolean. Set this to False if you want to disable Django's transaction management and implement your own.

• Trusted_Connection

  String. Default is "yes". Can be set to "no" if required.

and the following entries are also available in the TEST dictionary for any given database-level settings dictionary:

• NAME

  String. The name of database to use when running the test suite. If the default value (None) is used, the test database will use the name "test_" + NAME.

• COLLATION

  String. The collation order to use when creating the test database. If the default value (None) is used, the test database is assigned the default collation of the instance of SQL Server.

• DEPENDENCIES

  String. The creation-order dependencies of the database. See the official Django documentation for more details.

• MIRROR

  String. The alias of the database that this database should mirror during testing. Default value is None. See the official Django documentation for more details.

OPTIONS

Dictionary. Current available keys are:

• driver

  String. ODBC Driver to use ("ODBC Driver 17 for SQL Server", "SQL Server Native Client 11.0", "FreeTDS" etc). Default is "ODBC Driver 17 for SQL Server".

• isolation_level

  String. Sets transaction isolation level for each database session. Valid values for this entry are READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ, SNAPSHOT, and SERIALIZABLE. Default is None which means no isolation levei is set to a database session and SQL Server default will be used.

• dsn

  String. A named DSN can be used instead of HOST.

• host_is_server

  Boolean. Only relevant if using the FreeTDS ODBC driver under Unix/Linux.

  By default, when using the FreeTDS ODBC driver the value specified in the HOST setting is used in a SERVERNAME ODBC connection string component instead of being used in a SERVER component; this means that this value should be the name of a dataserver definition present in the freetds.conf FreeTDS configuration file instead of a hostname or an IP address.

  But if this option is present and its value is True, this special behavior is turned off. Instead, connections to the database server will be established using HOST and PORT options, without requiring freetds.conf to be configured.

  See https://www.freetds.org/userguide/dsnless.html for more information.

• unicode_results

  Boolean. If it is set to True, pyodbc's unicode_results feature is activated and strings returned from pyodbc are always Unicode. Default value is False.

• extra_params

  String. Additional parameters for the ODBC connection. The format is "param=value;param=value", Azure AD Authentication (Service Principal, Interactive, Msi) can be added to this field.

• collation

  String. Name of the collation to use when performing text field lookups against the database. Default is None; this means no collation specifier is added to your lookup SQL (the default collation of your database will be used). For Chinese language you can set it to "Chinese_PRC_CI_AS".

• connection_timeout

  Integer. Sets the timeout in seconds for the database connection process. Default value is 0 which disables the timeout.

• connection_retries

  Integer. Sets the times to retry the database connection process. Default value is 5.

• connection_retry_backoff_time

  Integer. Sets the back off time in seconds for reries of the database connection process. Default value is 5.

• query_timeout

  Integer. Sets the timeout in seconds for the database query. Default value is 0 which disables the timeout.

• setencoding and setdecoding

  # Example
  "OPTIONS": {
          "setdecoding": [
              {"sqltype": pyodbc.SQL_CHAR, "encoding": 'utf-8'},
              {"sqltype": pyodbc.SQL_WCHAR, "encoding": 'utf-8'}],
          "setencoding": [
              {"encoding": "utf-8"}],
          ...
          },
  

Backend-specific settings

The following project-level settings also control the behavior of the backend:

• DATABASE_CONNECTION_POOLING

  Boolean. If it is set to False, pyodbc's connection pooling feature won't be activated.

Example

Here is an example of the database settings:

    DATABASES = {
        'default': {
            'ENGINE': 'mssql',
            'NAME': 'mydb',
            'USER': 'user@myserver',
            'PASSWORD': 'password',
            'HOST': 'myserver.database.windows.net',
            'PORT': '',

            'OPTIONS': {
                'driver': 'ODBC Driver 17 for SQL Server',
            },
        },
    }

    # set this to False if you want to turn off pyodbc's connection pooling
    DATABASE_CONNECTION_POOLING = False

Limitations

The following features are currently not fully supported:

• Altering a model field from or to AutoField at migration
• Django annotate functions have floating point arithmetic problems in some cases
• Annotate function with exists
• Exists function in order_by
• Righthand power and arithmetic with datatimes
• Timezones, timedeltas not fully supported
• Rename field/model with foreign key constraint
• Database level constraints
• Math degrees power or radians
• Bit-shift operators
• Filtered index
• Date extract function
• Hashing functions

JSONField lookups have limitations, more details here.