Django Local Settings Installedapps Django DjangoUsing Python With Oracle Database 1.Do not delete this text because it is a placeholder for the generated list of main topics when run in a browser This tutorial shows you how to use Python with Oracle Database 1.Approximately 1 hour.Python is a popular general purpose dynamic scripting language.Django Local Settings Installed_apps Django Tutorial' title='Django Local Settings Installed_apps Django Tutorial' />With.Frameworks, Python is also becoming common for Web.If you want to use Python and an Oracle.Install Oracle Database 1.Create a user named PYTHONHOL with password ofwelcome.Install Oracles sample HR schema in PYTHONHOL andmake the following modifications Add a sequence and trigger to autopopulate the EMPLOYEEID field when new records are inserted.To simplify the example we remove this trigger otherwise records can only be updated once without violating the PYTHONHOL.JHISTEMPIDSTDATEPK constraintdrop trigger updatejobhistory Allow employees to be changed when testing the lab after hours.This is our instance of the library, you can have many instances but theres probably no reason for that when using Django.We also add the Django settings module.June 2017. This analysis is a comparison of 2 python web frameworks, Flask and Django.It discusses their features and how their technical philosophies impact.Install Python 2.Oracle 5. 1 extension 4.Install the Django 1.Extract these files.Move the files from the default directory to your HOME directory.The Django framework is one of several popular Python Frameworks for.Python web applications.Django is a Model View Controller framework.This section of the tutorial creates an Employee administration.Oracles Human Resources sample schema.The. schema has been slightly modified to simplify some aspects of the.Note Leading whitespace is significant in Python.Be careful when. changing code as you work through this tutorial.Indentation is used in Python to.There are no statement terminators unlike.Many of Djangos configuration files use.Python conventions.To start, create a Django project.From a terminal window, run.This creates a mysite directory in your home directory.It also generates code for a new Django project, including project settings and database configuration.Look at what startproject created ls lt mysite.You should see These files are init.An empty file telling Python to consider this directory a Python package.A command line script that allows the Django project to be administered.Settings for this Django project.The mappings for the project that maps URL requests to Django files.To run the skeleton application, in your terminal window, start the Django development web server cd HOMEmysite.The Django development web server has been started.Because this is a development web server, it should not be used in production.In the Firefox web browser go to http localhost 8.Press control C in the terminal window to terminate the web server.Setup the database connection information.Edit HOMEmysitesettings.Replace only the current DATABASES entry with DATABASES default ENGINE django.NAME localhostorcl,USER pythonhol,PASSWORD welcome,Make sure there is no whitespace before the keyword DATABASES.Save the file. This entry tells Django to use the Oracle interface, connecting to the.The username and.A Django project can be thought of as a website.An application is a.Inside the mysite project directory, create an application cd HOMEmysitepython manage.When the command succeeds, it finishes silently and creates a directory pythonhol for the new application.Note If you see an error such as pythonhollocalhost mysite python manage.Traceback most recent call last File manage.Assumed to be in the same directory.File homepythonholmysitesettings.DATABASES Syntax.Error invalid syntaxyou probably have whitespace before the DATABASES keyword in mysitesettings.Edit the file, remove the leading whitespace.Next, you need to define models for the application.Initially, HOMEmysitepythonholmodels.HOMEmysitepythonholmodels.Typically Django applications are written to auto generate tables from a new applications model.However, in this tutorial we create an application based on existing tables.Run cd HOMEmysitepython manage.This may take a few seconds to complete.This command interrogates the pythonhol schema and creates a model for each table.HOMEmysitepythonholmodels.You can see each table has a class with class variables for each column.The classes are subclasses of django.Model. Each field has a type.Many fields have a length that is used for validation.In new applications the length could be used to create the correct database schema.Django supports all of the common database relationships many to one, many to many, and one to one.The tutorial code focuses on employees and jobs, so the models not related to employees and jobs are not needed.Overwrite Djangos generated HOMEmysitepythonholmodels.HOMEsamplemodels.HOMEsamplemodels.HOMEmysitepythonholmodels.The HOMEmysitepythonholmodels.HOMEmysitepythonholmodels.Jobmodels. Model.Char. Fieldmaxlength1.True. jobtitle models.Char. Fieldmaxlength3.Integer. FieldnullTrue, blankTrue.Integer. FieldnullTrue, blankTrue.Meta. dbtable ujobs.Employeemodels. Model.Auto. FieldprimarykeyTrue.Char. Fieldmaxlength2.True. lastname models.Char. Fieldmaxlength2.Char. FielduniqueTrue, maxlength2.Char. Fieldmaxlength2.True. hiredate models.Date. Field. job models.Foreign. KeyJob. Decimal.FieldnullTrue, maxdigits8, decimalplaces2, blankTrue.Decimal. FieldnullTrue, maxdigits4, decimalplaces2, blankTrue.Foreign. Keyself, nullTrue, blankTrue.Integer. FieldnullTrue, blankTrue.Meta. dbtable uemployees.Job. Historymodels.Model. employee models.Foreign. KeyEmployee, primarykeyTrue.Date. FielduniqueTrue.Date. Field. job models.Foreign. KeyJob. Integer.FieldnullTrue, blankTrue.Meta. dbtable ujobhistory.The changes to models.The order of the models is changed because of model dependencies.For example, the EMPLOYEES table is dependent on the JOBS table so the Job model must occur before the Employee model.Django models use names in the singluar form.The generated ones are based on Oracles table names which are plural, so the model names were changed to singular.For example EMPLOYEES was changed to Employee.A def strself function was added to each model.This will come in handy later.The Employees employeeids models.Integer. Field was changed to.Auto. Field. This, with some help from a trigger and sequences, will auto increment the primary identifier when a new record is inserted.There were also changes to the foreign key fields, adding models.Foreign. Key. This is because inspectdb cannot recognize foreign key constraints so these have to be defined manually.The foreign key fields were renamed, removing the ID suffix.This is because Django will assume this suffix by default so including.JOBIDID does not exist.Edit the HOMEmysitesettings.Scroll to the bottom of the file.Change the INSTALLEDAPPS setting to include the string mysite.INSTALLEDAPPS. Uncomment the next line to enable the admin.Uncomment the next line to enable admin documentation.Save the file. The INSTALLEDAPPS variable holds the names of all applications that.The default applications that come.Django include django.An authentication system.A framework for content types.A session framework.A framework for managing multiple sites with one Django installation.These applications will not be discussed in this tutorial, but you will activate the.To activate the optional Django admin application, you must enable it in settings.URL mapping file.First, edit the HOMEmysitesettings.Change the INSTALLEDAPPS setting and uncomment the django. Free Download Driver Laptop Hp Mini 210 Series . INSTALLEDAPPS. Uncomment the next line to enable the admin.Uncomment the next line to enable admin documentation.Save the file. Next, synchronize the database cd HOMEmysitepython manage.Answer yes to the prompt to create a superuser.Accept the default username, specify pythonholexample.You will need the username and password later.This updates the database tables needed by the admin application.Feel free to look at the newly created tables in the database by using SQLPlus.DJANGO exit. This shows that Django has created tables such as DJANGOSITE and.DJANGOADMINLOG. Finally, update the URL mappings.Edit HOMEmysiteurls.Uncomment the three lines that reference the.This file maps URLs to application pages.In the end, you. should have a urls.Uncomment the next two lines to enable the admin.Examples. urlr, mysite.Uncomment the admindoc line below to enable admin documentation.Running a Django Application on Windows Server 2.IIS. Even if you already have IIS installed, you may need to go through these steps to install the CGI feature if it wasnt installed as part of the original IIS installation.Python virtual environments are used to isolate application specific Python environments from the system wide Python environment.Even if you will only be running one application on a server, its good practice to create a virtual environment for your application to keep the virtual environment free from any unanticipated side effects of system updates.With the virtual environment created, the next steps are to activate the virtual environment and update pip, Pythons package installer.Typically, youll be installing requirements from a requirements.Django in our virtual environment, both to illustrate the steps involved as well as to ensure the virtual environment is working properly.Then well create a sample Django application that well use later to configure with IIS.In the same Command Prompt you opened above, with the virtual environment activated, install Django pip install django then press EnterAs outlined in the prerequisites section at the beginning of this document, youll also need to install wfastcgi in order for IIS to be able to pass requests off to Django pip install wfastcgi then press EnterNavigate to the root of the C drive cd C then press EnterCreate a new directory in which well put our application mkdir apps then press EnterNavigate to the newly created apps directory cd apps then press EnterCreate a new Django project called foo django admin.EnterNavigate to the newly created foo project directory cd foo then press EnterStart the Django development server python manage.EnterYou should see the following output In a browser on the server, go to http localhost 8.You should see the following Go back to the Command Prompt and press Ctrl C to stop the Django development server.Configure IIS to Serve Django Applications.Thus far weve accomplished the following Installed Python.Installed IIS with CGICreated and activated a Python virtual environment.Installed Django and wfastcgi in a Python virtual environment.Created a new Django project.Ran the Django project using the Django development server.With all the underlying infrastructure in place, the last step is to configure IIS to serve Django applications.The Django development server is not designed for production use, so using a production quality web server such as IIS is mandatory for production applications.As with previous steps youll need to adjust accordingly for the actual application you want to deploy, but for the purposes of this documentation well configure IIS to serve the test Django application we created in the previous steps.Configure Fast. CGI in IISOpen the IIS Manager by clicking the Windows button, clicking on Administrative Tools, and double clicking Internet Information Services IIS Manager.Click on the name of the server in the list on the left.If you see the following dialog box, check the box Do not show this message and click No.You can always get to this later if necessary by clicking Get New Web Platform Components under Actions on the right hand side of IIS Manager.Double click the Fast.CGI Settings icon.Under Actions on the right hand side click Add application.In the Add Fast. CGI Application dialog, in the Full Path box, type the path to the Python executable for the applications virtual environment C virtualenvsfooScriptspython.In the Arguments input box, type the path to the wfastcgi.C virtualenvsfooLibsite packageswfastcgi.At this point your settings in the Add Fast.CGI Application dialog should look like this With the Add Fast.CGI Application dialog box still open, under the General section, click on the Environment Variables line, then click the gray.Collection on the right hand side of the line.This opens the Environment.Variables Collection Editor dialog.In the Environment.Variables Collection Editor dialog, click AddIn the Name properties section on the right, click the input box to the right of Name, remove the Name text that is already in the input box, and enter DJANGOSETTINGSMODULE note that this MUST be entered in ALL CAPSClick the input box to the right of Value and enter foo.Click Add again and enter the following Name PYTHONPATHValue C appsfoo.Click Add again and enter the following Name WSGIHANDLERValue django.At this point you will have three environment variables NOTE All of these settings are CASE SENSITIVE.They must be entered with exactly the case indicated here in order to work.Click OK to close the Enviroment.Variables Collection Editor.Click OK to close the Add Fast.CGI Application dialog.Create and Configure a New IIS Web Site.Next we need to create a new web site in IIS for the Django application, and add a Handler Mapping to the newly created web site so that requests coming to the IIS web site are passed off to the Django application for processing.Open IIS Manager.On the left hand side under Connections, expand the tree under the server name by clicking on the arrow to the left of the server name.Right click on the Sites folder and click Add Website.For the site name enter foo.For the physical path, type the following C appsfoo.For the purposes of this example configuration, change the Port to 8.Default site is running on port 8.For a real world application youll likely want to use name based virtual hosting by adding bindings and run the site on port 8.You may leave the Host name blank.At this point the Add Website dialog should look like this Click OK.Next, well add a Fast.CGI handler mapping to this site so the requests coming into the site will be processed by the Django application.In IIS Manager, expand the Sites folder on the left hand side and click on the foo site.On the right, double click Handler MappingsOn the right, under Actions, click Add Module MappingIn the Request path box enter an asterisk lick the arrow on the right hand side of the Module box and select Fast.Cgi ModuleNOTE Make sure to select Fast.Cgi Module, NOT Cgi.Module. In the Executable box, enter the following C virtualenvsfooScriptspython.C virtualenvsfooLibsite packageswfastcgi.Note that the character after python.Shift on your keyboard.In the Name box, enter Django Handler you can call this whatever you want its merely a friendly name for the module mappingThe Add Module Mapping dialog should now look like this Click the Request Restrictions button and uncheck the Invoke handler only if request is mapped to checkbox.Click OK to close the Request Restrictions dialog.Click OK to close the Add Module Mapping dialog.When prompted Do you want to create a Fast.CGI application for this executable click No since we created the application earlier.Note that you CAN have it create the Fast.CGI application for you from the module mapping, but the settings seem to be different and the end result isnt fully editable.I also detailed how to create the Fast.CGI application to be as thorough as possible with all the various pieces involved.You will now see the Django Handler listed in the Handler Mappings for the foo website.At this point everything should be working, so verify by loading the application in a browser.Open a browser on the server.Browse to http localhost 8.You should see the following.This is the same result as when we ran the Django test server earlier, but now the requests are being handled by IIS.Configure Django and IIS to Serve Static Files.Now we have things more or less working but we arent quite done.If you browse to the Django admin page http localhost 8.The reason things look a little strange is because IIS doesnt know where things like the CSS and image files for the Django application are located.In the Django world these assets are referred to as static files, and we need to perform a couple of additional steps for IIS to be able to serve these files.This isnt an issue during development since Django has a static file server built into it, but in production well want IIS to handle serving these files.How Django handles static files is a bit of a topic in and of itself, so for further information please consult the Django documentation https docs.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |