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 Database such as MySQL, GadFly, mySQL, 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 module. Below is a program to connect with MySQL database geeks.
Python# importing required libraryimportmysql.connector# connecting to the databasedataBase=mysql.connector.connect(host="localhost",user="user",passwd="pswrd",database="geeks")# preparing a cursor objectcursorObject=dataBase.cursor()# disconnecting from serverdataBase.close()
The above program illustrates the connection with the MySQL database geeks in which host-name is localhost, the username is user and password is pswrd.
Select Query
After connecting with the database in MySQL we can select queries from the tables in it.Syntax:
- In order to select particular attribute columns from a table, we write the attribute names.
SELECT attr1, attr2 FROM table_name
- In order to select all the attribute columns from a table, we use the asterisk '*' symbol.
SELECT * FROM table_name
Example 1: Let's consider the table looks like this -
Below is a program to select a query from the table in the database.
Python# importing required libraryimportmysql.connector# connecting to the databasedataBase=mysql.connector.connect(host="localhost",user="user",passwd="pswrd",database="geeks")# preparing a cursor objectcursorObject=dataBase.cursor()print("Displaying NAME and ROLL columns from the STUDENT table:")# selecting queryquery="SELECT NAME, ROLL FROM STUDENT"cursorObject.execute(query)myresult=cursorObject.fetchall()forxinmyresult:print(x)# disconnecting from serverdataBase.close()Output:
Example 2: Let us look at another example for selecting queries in a table.
Python# importing required libraryimportmysql.connector# connecting to the databasedataBase=mysql.connector.connect(host="localhost",user="user",passwd="pswrd",database="geeks")# preparing a cursor objectcursorObject=dataBase.cursor()print("Displaying NAME and ROLL columns from the STUDENT table:")# selecting queryquery="SELECT * FROM STUDENT"cursorObject.execute(query)myresult=cursorObject.fetchall()forxinmyresult:print(x)# disconnecting from serverdataBase.close()Output: