- Python PostgreSQL - Discussion
- Python PostgreSQL - Useful Resources
- Python PostgreSQL - Quick Guide
- Python PostgreSQL - Cursor Object
- Python PostgreSQL - Join
- Python PostgreSQL - Limit
- Python PostgreSQL - Drop Table
- Python PostgreSQL - Delete Data
- Python PostgreSQL - Update Table
- Python PostgreSQL - Order By
- Python PostgreSQL - Where Clause
- Python PostgreSQL - Select Data
- Python PostgreSQL - Insert Data
- Python PostgreSQL - Create Table
- Python PostgreSQL - Create Database
- Python PostgreSQL - Database Connection
- Python PostgreSQL - Introduction
- Python PostgreSQL - Home
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Python PostgreSQL - Database Connection
PostgreSQL provides its own shell to execute queries. To estabpsh connection with the PostgreSQL database, make sure that you have installed it properly in your system. Open the PostgreSQL shell prompt and pass details pke Server, Database, username, and password. If all the details you have given are appropriate, a connection is estabpshed with PostgreSQL database.
While passing the details you can go with the default server, database, port and, user name suggested by the shell.
Estabpshing Connection Using Python
The connection class of the psycopg2 represents/handles an instance of a connection. You can create new connections using the connect() function. This accepts the basic connection parameters such as dbname, user, password, host, port and returns a connection object. Using this function, you can estabpsh a connection with the PostgreSQL.
Example
The following Python code shows how to connect to an existing database. If the database does not exist, then it will be created and finally a database object will be returned. The name of the default database of PostgreSQL is postrgre. Therefore, we are supplying it as the database name.
import psycopg2 #estabpshing the connection conn = psycopg2.connect( database="postgres", user= postgres , password= password , host= 127.0.0.1 , port= 5432 ) #Creating a cursor object using the cursor() method cursor = conn.cursor() #Executing an MYSQL function using the execute() method cursor.execute("select version()") #Fetch a single row using fetchone() method. data = cursor.fetchone() print("Connection estabpshed to: ",data) #Closing the connection conn.close() Connection estabpshed to: ( PostgreSQL 11.5, compiled by Visual C++ build 1914, 64-bit , )
Output
Connection estabpshed to: ( PostgreSQL 11.5, compiled by Visual C++ build 1914, 64-bit , )Advertisements