Create a blog app using Web2py

1. Start web2py
2. Usually blog will have post and view the post details
3. Validations required to validate the post
4. Database design to store title, content, image category , blog posted date etc..
First we need to create model



5. Edit the db.py file
6.End of the file add the below code, to create a table 'blog' along with columns

db.define_table('blog',
                 Field('blog_title'),
                 Field('blog_details'),
                 Filed('blog_image'),
                 Field('blog_url'),
                 Field('blog_category'),
                 Field('blog_date_posted'))

We need to use validators inside model, more validators look inside

http://web2py.com/examples/static/web2py_cheatsheet.pdf

db.define_table('blog',
                 Field('blog_title', requires=IS_NOT_EMPTY()),
                 Field('blog_details', type='text'),
                 Filed('blog_image',requires=IS_URL()),
                 Field('blog_url',requires=IS_URL()),
                 Field('blog_category',requires=IS_IN_SET(['News','Events','Technology','Business'])),
                 Field('blog_date_posted', type='date',requires=IS_DATE()))

  

7. Need to add validation for table details


8.Now we need to create a controller, to post the blog app
9.Create controller name called blog under controller section
10.Edit blog.py
11. Add two methods one is called post and one is view

def post():
       form =SQLFORM(db.blog).process()
       return locals()
      def view():
      rows = db(db.blog).select(orderby=~db.blog.id)
      return locals()

   

12.Now we need to create views as blog/post and blog/view
13.Edit the blog/post.py

{{extend 'layout.html'}}
     
post a blog as you like
{{=form}}
  

http://127.0.0.1:8000/sivaweb2py/blog/post


14.If you submit without entering any values, then it will show the validation errors






Provide the details as required and submit the same. You can see the success message.

Need to know more about SQLFORMS and validators
http://web2py.com/books/default/chapter/29/07/forms-and-validators
Now we need to update the blog

Edit the blog.py and add the below code for update method

def update():
    record = db.blog(request.args(0)) or redirect (URL(post))
    form = SQLFORM(db.blog,record)
    if form.process().accepted:
        response.flash = T('Record Updated')
    else:
        response.flash=T('Please complete the form')
    return locals()

Create update view under views section

{{extend 'layout.html'}}
            
Update the form
{{=form}}
      
       

Click on the below link to update the record or provide number after update method which ever record want to update
http://127.0.0.1:8000/sivaweb2py/blog/update/1



Now we need to create the view page

{{extend 'layout.html'}}
      
View the blog
{{ for x in rows:}}
     

       
{{=x.blog_title}}
        
 categrory:{{=x.blog_category}}
     
 blog Details:{{=x.blog_details}}  
 blog posted:{{=x.blog_date_posted}} 
{{ pass }}

 

After adding the above code in view.py, if we check the result using below url
http://127.0.0.1:8000/sivaweb2py/blog/view




This is how we can create a blog app using web2py.

Getting started with web2py framework

    Full Stack web development with Python (Web2Py)
    How to download and install web2py
1.  Go  to http://web2py.com/

2.   Down load latest version http://web2py.com/init/default/download

     Unzip the downloaded file

     CliCk on the Web2py.exe file to it will open the window like below

           Provide the password(any password) and start the server

           Server has been started. Now we need to create a application using web2py framework.

           http://localhost:8000

                                                

         Click on the Admin,  which is there on the right side in the page. And provide the password which      we have given while starting the server

                After Successful Login,  page will be open like below.

               Create a new application using this framework- > New simple application –

       Application Name - ex: sivaweb2py

              Click on the create button. Now we have created application successfully.

               Need to run the application

               http://localhost:8000/sivaweb2py

               

              Now we need to write sample code in this application. So we need to understand basics of  the
       framework

               Need to edit the application

      This framework will follow MVC architecture

          Model- Contains db details

         Controller – Method and logic details

         Views – Html input/output to the user

Now we need to create one controller and respective views

Click on the Create button under Controller Section

I have given controller name as basics – basics.py will be created under controller

       Now edit the controller – Click on the basics.py

     def helloworld():
     msg= "Hello welcome to basics controller!"
     return locals()

 In the above code helloworld is method name . Copy the code and paste the same in your file.

  Save the file and go to back – by click on the back buton

  Now we need to create a  view- under Views section

  View name should be as method name  ex: basics/helloworld

   {{extend 'layout.html'}}

    This is our first web page
   {{ =msg}}

   Writing first web2py is very easy

                          

   http://localhost:8000/sivaweb2py/basics/helloworld

        

                               

Getting started with Oracle Stored Procedure and parse clob xml data and cursor

This Post will having the details to create stored procedure in oracle and parsing the clob data through stored procedure.

employee.xml
-------------


  siva
  32
  M

Above xml will be stored as clob data in Person table

Person table Schema -

Id NUMBER,
Name Varchar2(50),
employee_details clob

Above xml will be stored as clob data in Person table

create table PERSON (Id NUMBER, Name varchar2(50), employee_details clob);
  create table EMPLOYEE (Name varchar2(50), age NUMBER ,sex varchar2(10));

We need to parse the clob data using oracle procedure

create or replace PROCEDURE SP_PARSE_CLOB (person_id NUMBER) AS
  PERSION_ID Person.id%type;
  PERSON_NAME Person.name%type;
  EMPLOYEE_DETAILS Person.employee_details%type;
  name varchar2(50);
  age varchar2(50);
  sex varchar2(50);
  EMPLOYEE_exc EXCEPTION;
  -- Create a cursor
 cursor personDataCursor IS SELECT id, Name,employee_details from PERSON;
 BEGIN
   OPEN personDataCursor;
 LOOP
 FETCH personDataCursor into PERSION_ID,PERSON_NAME,EMPLOYEE_DETAILS;
 EXIT WHEN personDataCursor%notfound;
 IF XMLTYPE(EMPLOYEE_DETAILS).existSNode('/Employee/name/text()') > 0 THEN
   name := XMLTYPE(EMPLOYEE_DETAILS).extract('/Employee/name/text()').getStringVal();
 END IF;
 IF XMLTYPE(EMPLOYEE_DETAILS).existSNode('/Employee/age/text()') > 0 THEN
  age := XMLTYPE(EMPLOYEE_DETAILS).extract('/Employee/age/text()').getStringVal();
 END IF;
 IF XMLTYPE(EMPLOYEE_DETAILS).existSNode('/Employee/sex/text()') > 0 THEN
  sex := XMLTYPE(EMPLOYEE_DETAILS).extract('/Employee/sex/text()').getStringVal();
 END IF;
 dbms_output.put_line('Name:'|| name|| ' ' || 'Age:' || ' ' ||age || ' ' || 'Sex:' || ' ' || sex);
 -- Inset into another table
BEGIN
  insert into EMPLOYEE(name,age,sex) values(name,age,sex);
 EXCEPTION
    WHEN OTHERS
   THEN
    RAISE EMPLOYEE_exc;
  END;
  commit;
  END LOOP;

EXCEPTION
    WHEN EMPLOYEE_exc
      THEN
        rollback;
     -- Do what ever you want like insert log details in any another table
    commit;
    DBMS_OUTPUT.PUT_LINE ('Insertion failed in EMPLOYEE : '|| '' || name);
    END;

ArithmeticOperations Example using Python

Arithmetic operation using python in windows.
In my previous post , I have written how to install python in windows and add plugin into eclipse.


In this post I am going to explain simple arithmetic operations.

Step 1: Open eclipse - File - New - PyDev Project - arithmeticoperation_test
Step 2: Right click on the - src - New- PyDevModule- ArithmeticOperation
Step 3:Paste below code into ArithmeticOperation.py file.

'''
Created on 07-Dec-2015


@author: rajusiva

'''
a = input("Enter a value:")
b = input("Enter b value:")
print("Addition of 2 values is[",int(a)+int(b),"]")
print("subtract of 2 values is[",int(a)-int(b),"]")
print("Multiply of 2 values is[",int(a)*int(b),"]")
print("Division of 2 values is[",int(a)/int(b),"]")
print("Exponent of 2 values is[",int(a)**int(b),"]")
print("Modules of 2 values is[",int(a)%int(b),"]")
print("Floor Division of 2 values is[",int(a)//int(b),"]")

Step 4: Right click on the program-Run As- Python Run
Step 5: output as follows

Enter a value:25
Enter b value:10
Addition of 2 values is[ 35 ]
subtract of 2 values is[ 15 ]
Multiply of 2 values is[ 250 ]
Division of 2 values is[ 2.5 ]
Exponent of 2 values is[ 95367431640625 ]
Modules of 2 values is[ 5 ]
Floor Division of 2 values is[ 2 ]