Chapter 6 Interface Python with MYSQL.pptx

CHAPTER - XVI
INTERFACE PYTHON WITH MYSQL

REFERENCE:
CLASS XII
TEXT BOOK
SUMITA ARORA

INTRODUCTION
Every organisation depends on
large databases. These are essentially
collections of tables, and’ connected with
each other through columns. These database
systems support SQL, the Structured Query
Language, which is used to create, access and
manipulate the data.

INTRODUCTION
The Python programming language has
powerful features for database programming.
Python supports various databases like
MySQL, Oracle, Sybase, PostgreSQL, etc.
Python also supports Data Definition
Language (DDL), Data Manipulation Language
(DML) and Data Query Statements.

INTRODUCTION
For database programming, the Python DB
API is a widely used module that provides a
database application programming interface.

INTERFACE
What is an Interface?
Interface is the way for an application to
interact with certain system/application.

API - APPLICATION PROGRAMMING INTERFACE

API -APPLICATION PROGRAMMING INTERFACE
In computer programming, an
application programming interface is a set of
subroutine definitions, communication
protocols, and tools for building software. In
general terms, it is a set of clearly defined
methods of communication among various
components.

Consider an API as a waiter in a
restaurant. Suppose you have a menu of your
favourite food and the kitchen is the system
where your order is made. But how do you
take your order till the kitchen? Correct, you
call a waiter, give him/her the order, which in
turns takes your order till the kitchen and
then your order is made there and then
finally, the waiter comes back with your
delicious ordered food.

Thus, the API is very much similar to the
waiter. API is the messenger that takes your
order(waiter) and tells the system(kitchen)
what to do (to prepare food) and in return
gives back the response you asked for (waiter
returns with the ordered food).

BENEFITS OF PYTHON FOR DATABASE
PROGRAMMING

There are many good reasons to use Python for
programming database applications:
Programming in Python is arguably more
efficient and faster compared to other
languages.
Python is famous for its portability.
It is platform independent.
PROGRAMMING

Python supports SQL cursors.
In many programming languages, the
application developer needs to take care of the
open and closed connections of the database, to
avoid further exceptions and errors. In Python,
these connections are taken care of.
PROGRAMMING

Python supports relational database systems.
Python database APIs are compatible with
various databases, so it is very easy to migrate
and port database application interfaces.
PROGRAMMING

PYTHON INTEGRATION WITH MYSQL
We discuss how to develop and integrate
Python applications that work with a MySQL
database server. Python is dynamic, and
enterprise language and it has all the support
to build large and complex enterprise
applications. MySQL is the world’s most
powerful and used open-source database
provided by Oracle.
INTRODUCTION

PYTHON MODULE FOR COMMUNICATING WITH MYSQL

Total 5 modules available in python to
communicate with a MySQL and provides
MySQL database support to our applications
and they are:-
1. MySQL Connector Python
2. PyMySQL
3. MySQLDB
4. mysqlclient
5. OurSQL

Note: Above all interfaces or modules are
adhere to Python Database API Specification
v2.0 (PEP 249) that means the syntax, method
and the way of access database is the same in
all.
PEP 249 has been designed to encourage
and maintain similarity between the Python
modules that are used to access databases. By
doing this, above all modules are following
rules defined in Python Database API
Specification v2.0 (PEP 249).

You can choose any of the above modules
as per your requirement. The way of accessing
the MySQL database remains the same. We
discuss
MySQL Connector Python
Throughout this chapter.

MYSQL CONNECTOR PYTHON

What is MYSQL Connector Python?
MYSQL Connector Python is module
or library available in python to
communicate with a MySQL
MYSQL CONNECTOR PYTHON

ADVANTAGES OF MYSQL CONNECTOR PYTHON

 MySQL Connector Python is written in pure
Python, and it is self-sufficient to execute
database queries through python.
It is an official Oracle-supported driver to
work with MySQL and python.
It is Python 3 compatible, actively
maintained.
ADVANTAGES OF MYSQL CONNECTOR PYTHON

INSTALLATION : MYSQL CONNECTOR PYTHON

PREREQUISITES
You need root or administrator privileges to perform
the installation process.
Python must installed on your machine.
Note: – MySQL Connector Python requires python to be
in the system’s PATH. Installation fails if it doesn’t find
Python.
On Unix and Unix-like systems, Python generally
located in a directory included in the default PATH
setting.
On Windows, If Python doesn’t exist in the system’s
PATH, please manually add the directory containing
python.exe yourself.

PLATFORM
Platform(s): 64-bit Windows, Windows 10, Windows
7, Windows 8, Windows Vista, Windows XP, Linux,
Ubuntu Linux, Debian Linux, SUSE Linux, Red Hat Linux,
Fedora, MacOs.
Python version(s): Python 2 and 3 and above.
MySQL Version(s): Greater than 4.1

WAYS TO INSTALL MySQL Connector Python

There are multiple ways to install Oracle’s
MySQL Connector Python on your machine.
Following are the few ways.
Install MySQL Connector Python using the pip
command.
Install MySQL connector python via source
code (via ZIP or TAR file)

Use Built Distribution A package created in
the native packaging format intended for a
given platform. Example, RPM packages for
Linux or MSI installer for windows.

PIP Command to install MySQL Connector
Python

PIP Command to install MySQL Connector
Python
pip install mysql-connector-python
If you are facing any problem while installing,
please mention the version of the module and then try
to install again. Refer to the above table to install the
correct version.
pip install mysql-connector-
python==8.0.11

PYTHON MySQL DATABASE CONNECTION

PYTHON MySQL DATABASE CONNECTION
Goals - In this session, you’ll learn:
How to connect MySQL Server and create a
table in MySQL from Python.
Different MySQL Connection arguments we
can use to connect to MySQL.
How to change the MySQL connection
timeout when connecting through Python.

ARGUMENTS REQUIRED TO CONNECT MYSQL
FROM PYTHON

FROM PYTHON
You need to know the following detail of the
MySQL server to perform the connection from
Python.
Username – i.e., the username that you use
to work with MySQL Server. The default
username for the MySQL database is a root
Password – Password is given by the user at
the time of installing the mysql database. If you
are using root then you won’t need the
password.

FROM PYTHON
Host Name – is the server name or Ip address
on which MySQL is running. if you are running
on localhost, then you can use localhost, or it’s
IP, i.e. 127.0.0.0
Database Name – Database name to which
you want to connect.

STEPS TO CONNECT MYSQL DATABASE IN
PYTHON USING MySQL Connector Python

Install MySQL Connector Python using pip.
Use the mysql.connector.connect() method
of MySQL Connector Python with required
parameters to connect MySQL.
Use the connection object returned by
a connect() method to create a cursor object to
perform Database Operations.

The cursor.execute() to execute SQL queries
from Python.
Close the Cursor object using
a cursor.close() and MySQL database connection
using connection.close() after your work
completes.
Catch Exception if any that may occur during
this process.

Follow the steps:-
Step 1: Start the Python
Step 2: Import Package
Step 3: Open Connection or Connect to
database
Step 4: Create a cursor
Step 5: Execute Query
Step 6 Extract data from the result set
Step 7. Close the connection or clean up the
environment.

Step 1: Start the Python
Start the Python IDLE editor to write the
script
Step 2: Import MySQL Connector Python
Package.
import mysql.connector
Or
import mysql.connetor as SQLCon

database.
Mycon=mysql.connector.connect(
host='localhost',
database='mysql',
user='root',
password='')

database.
Mycon=mysql.connector.connect(
host='localhost',
database='mysql',
user='root',
password='')
Mycon is a connection object

What is Database Connection Object?
A Database connection object controls the
connection to the database. It represents a
unique session with a database connected from
within a script or program

One can check the connection by writing
the following code.
If mycon.is_connected():
print(“Successfully Connected”)

What is cursor?
A database cursor is a special control
structure that facilitates the row by
processing of records in the result set.
What is result set?
Result set refers to the logical set of
records that are fetched from the database
by executing an SQL query. It is the set of
records retrieved as per the query.

Step 4: Create a cursor.
Cursor object=
connectionobject.cursor()
For example:
EmpCursor = mycon.cursor()
Mycon is a connection object
Cursor Object

Step 5: Execute Query
EmpCursor.execute(“select * from
emp”)

Step 6: Extract data from the result set.
After retrieving the records from the
DB using SQL Select Query. You need to extract
records from the result set.

You can extract the result set using any of
the following fetch functions/ cursor methods.
.fetchone() .fetchall()
.fetchmany(n)
.close()
Cursor other methods are: -
.callproc() .nextset()

.fetchone()
1
Fetch the next row of a query result set,
returning a single sequence, or None when no
more data is available
Data=EmpCursor.fetchone()
V_count=EmpCursor.rowcount
print(“Total Rows retrieved : “,V_count)
print(data)

.fetchmany(n)
2
Fetch many(n) method will return only the
n number of rows from the result set in the
form of tuple containing the records.
Data=empcursor.fetchmany(4)
for row in data:
print(row)

.fetchall()
3
Fetch all method will return all the rows
from the result set in the form of tuple
containing the records.
Data=EmpCursor.fetchall()
for row in data:
print(row)

Step 7. Close the connection or clean up the
environment.
Syntax:
Connectionobject.close()
Example:
Mycon.close()

Python Program to Create Table
import mysql.connector as mysql
db = mysql.connect( host = "localhost", user =
"root", passwd = "dbms", database =
“Employee2019" )
cursor = db.cursor()
cursor.execute("CREATE TABLE users (name
VARCHAR(255), user_name VARCHAR(255))")

CREATING TABLE - PYTHON PROGRAM

Python Program to Create Table
"root", passwd = "dbms", database =
“Emp2019" )
cursor.execute("CREATE TABLE users (name
VARCHAR(255), user_name VARCHAR(255))")
CREATING TABLE - PYTHON PROGRAM

SHOW ALL TABLES - PYTHON PROGRAM

Python Program to show all tables.
"root", passwd = "", database = “Emp2019" )
cursor.execute("SHOW TABLES")
tables = cursor.fetchall()
for table in tables:
print(table)
SHOW ALL TABLES - PYTHON PROGRAM

PARAMETERISED QUERIES
You can run the queries with parameters
For example:
V_marks=56
Select * from student where marks>v_marks
These kind of queries are called as
parameterised queries.

PARAMETERISED QUERIES
FORMING QUERY STRINGS

To form a parameterised queries there are
two methods.
1. % formatting – (OLD STYLE)
2. .format() – (NEW STYLE )

S= “Select * from emp where empid=%s
and dept=‘%s’ “ % ( 1006 , ‘Biotech’)
Example 2: Another Method to use %s :-
Ram=8
Id=2
Input=(ram,id)
Qry= “Update comp set ram=%s where id=%s”
Cursor.execute(Qry,input)

The string formatting uses the following
style:
f % v
Where f is the string template and
v is the value.
For example:
S=“SELECT * FROM STUDENT WHERE
MARKS>%s” %(70,) v

New style of creating SQL Query stringss
involves the use of .format() method of the str
type.
“We have {0} hectares planted to {1}”
.format(49,”Okra”)
Resultant string will be:
“We have 49 hectares planted to okra”
Contd…

SQL_St=“Select * from student where
makrs>{} and section=‘{}’ “ .format(70,’B’)
After execution SQL_St variable stores:-
“Select * from student where marks >70 and
section=‘B’

INSERT AND UPDATE QUERIES
INSERT QUERY

INSERT QUERY
To Insert a record in a table use cursor
object. When you perform insert or update
remember to commit the transaction.
MyQuery=“Insert into student ( rollno,name,
marks) values ({},’{}’,{} ) “
.format(1203,’Raman’,67.6)
Cursor.execute(MyQuery)
Mycon.execute()

UPDATE QUERY

To Update a record in a table use cursor
object. When you perform insert or update
remember to commit the transaction.
MyQuery=“update student set marks={}“ where
marks={}” .format(84,66)
Cursor.execute(MyQuery)
Mycon.execute()
UPDATE QUERY

Chapter 6 Interface Python with MYSQL.pptx

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