Python Database API ( Application Program Interface ) is the Database interface for the standard Python. This standard is adhered to by most Python Database interfaces. There are various Database servers supported by Python Databases such as MySQL, GadFly, PostgreSQL, Microsoft SQL Server 2000, Informix, Interbase, Oracle, Sybase, etc. To connect with MySQL database server from Python, we need to import the mysql.connector interface. Below is a program to connect with MySQL database Lazyroar.
Python
# importing required library import mysql.connector # connecting to the database dataBase = mysql.connector.connect( host = "localhost", user = "user", passwd = "pswrd", database = "Lazyroar" ) # preparing a cursor object cursorObject = dataBase.cursor() # disconnecting from server dataBase.close() |
The above program illustrates the connection with the MySQL database Lazyroar in which host-name is localhost, the username is user and password is pswrd.
Deleting query from tables
After connecting with the database in MySQL we can create tables in it and can manipulate them. Syntax Statement:
DELETE FROM TABLE_NAME WHERE ATTRIBUTE_NAME = ATTRIBUTE_VALUE
Example 1: Below is a program to delete a query from the table in the database.
Python
# importing required library import mysql.connector # connecting to the database dataBase = mysql.connector.connect( host = "localhost", user = "user", passwd = "pswrd", database = "Lazyroar" ) # preparing a cursor object cursorObject = dataBase.cursor() # creating table studentRecord = """CREATE TABLE STUDENT ( NAME VARCHAR( 20 ) NOT NULL, BRANCH VARCHAR( 50 ), ROLL INT NOT NULL, SECTION VARCHAR( 5 ), AGE INT )""" # table created cursorObject.execute(studentRecord) # inserting data into the table query = "INSERT INTO STUDENT (NAME, BRANCH, ROLL, SECTION, AGE) VALUES ( % s, % s)" attrValues = ("Rituraj Saha", "Information Technology", " 1706256 ", "IT - 3 ", " 20 ") cursorObject.execute(query, attrValues) attrValues = ("Ritam Barik", "Information Technology", " 1706254 ", "IT - 3 ", " 21 ") cursorObject.execute(query, attrValues) attrValues = ("Rishi Kumar", "Information Technology", " 1706253 ", "IT - 3 ", " 21 ") cursorObject.execute(query, attrValues) # deleting query query = "DELETE FROM STUDENT WHERE ROLL = 1706256 " cursorObject.execute(query, attrValues) dataBase.commit() # disconnecting from server dataBase.close() |
Output: In the above program, a table named STUDENT is created having attributes NAME, BRANCH, ROLL, SECTION and AGE. Multiple data is inserted into the STUDENT table and then a single query is deleted from the table having the ROLL attribute value 1706256. Example 2: Let us look at another example for queries in a table.
Python
# importing required library import mysql.connector # connecting to the database dataBase = mysql.connector.connect( host = "localhost", user = "user", passwd = "pswrd", database = "Lazyroar" ) # preparing a cursor object cursorObject = dataBase.cursor() # drop table if it already exists cursorObject.execute("DROP TABLE IF EXISTS PHONE_RECORD") # creating table phoneRecord = """CREATE TABLE PHONE_RECORD ( NAME VARCHAR( 20 ) NOT NULL, PHONE VARCHAR( 10 ) NOT NULL )""" # table created cursorObject.execute(phoneRecord) # inserting data into the table query = "INSERT INTO PHONE_RECORD (NAME, PHONE) VALUES ( % s, % s)" attrValues = ("Rituraj Saha", " 9163089075 ") cursorObject.execute(query, attrValues) # deleting query query = "DELETE FROM STUDENT WHERE NAME = 'Rituraj Saha' " cursorObject.execute(query) dataBase.commit() # disconnecting from server dataBase.close() |
Output: In the above program, another table is created in the Lazyroar database named PHONE_RECORD having attribute NAME and PHONE. Only one column is inserted into the table and then it is deleted using the DELETE statement.