Python and PostgreSQL - Inserting Data
In order to insert data into a PostgreSQL database, the SQL ‘Insert’ statement needs to be used. The following example inserts a record into the same ‘person’ table that was used in the example for selecting data.
Inserting data works in a similar fashion as selecting data using parameters. Firstly, a connection to the database is established, then the query parameters are defined as variables, which are then bound in to the SQL statement when it is executed and a confirmation message is displayed. The execution of the SQL statement is wrapped in a ‘try-except-finally’ block to catch any errors that may arise and close the database connection at the end.
import psycopg2 # Database connection variable. connect = None try: # Connect to database. connect = psycopg2.connect(host='localhost', database='Demo', user='DemoUN', password='DemoPW;') except psycopg2.DatabaseError as e: # Confirm unsuccessful connection and stop program execution. print("Database connection unsuccessful.") quit() # Cursor to execute query. cursor = connect.cursor() # Query parameters. firstname = "Fiona" lastname = "Jones" title = "Miss" dob = "1985-05-19" # SQL to insert data into the person table. sqlInsert = \ "INSERT INTO person (firstname, lastname, title, dob) \ VALUES (%s, %s, %s, %s)" try: # Execute query and commit changes. cursor.execute(sqlInsert, (firstname, lastname, title, dob)) connect.commit() # Confirm successful addition of person information. print("Person information added successfully.") except psycopg2.DatabaseError as e: # Confirm error adding person information and stop program execution. print("Error adding person information.") quit() finally: # Close database connection. connect.close()
The contents of the ‘person’ table now looks as follows.