Python PostgreSQL - Insert Data


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You can insert record into an existing table in PostgreSQL using the INSERT INTO statement. While executing this, you need to specify the name of the table, and values for the columns in it.

Syntax

Following is the recommended syntax of the INSERT statement −

INSERT INTO TABLE_NAME (column1, column2, column3,...columnN)
VALUES (value1, value2, value3,...valueN);

Where, column1, column2, column3,.. are the names of the columns of a table, and value1, value2, value3,... are the values you need to insert into the table.

Example

Assume we have created a table with name CRICKETERS using the CREATE TABLE statement as shown below −

postgres=# CREATE TABLE CRICKETERS (
   First_Name VARCHAR(255),
   Last_Name VARCHAR(255),
   Age INT,
   Place_Of_Birth VARCHAR(255),
   Country VARCHAR(255)
);
CREATE TABLE
postgres=#

Following PostgreSQL statement inserts a row in the above created table −

postgres=# insert into CRICKETERS 
   (First_Name, Last_Name, Age, Place_Of_Birth, Country) values
   ('Shikhar', 'Dhawan', 33, 'Delhi', 'India');
INSERT 0 1
postgres=#

While inserting records using the INSERT INTO statement, if you skip any columns names Record will be inserted leaving empty spaces at columns which you have skipped.

postgres=# insert into CRICKETERS 
   (First_Name, Last_Name, Country) values('Jonathan', 'Trott', 'SouthAfrica');
INSERT 0 1

You can also insert records into a table without specifying the column names, if the order of values you pass is same as their respective column names in the table.

postgres=# insert into CRICKETERS values('Kumara', 'Sangakkara', 41, 'Matale', 'Srilanka');
INSERT 0 1
postgres=# insert into CRICKETERS values('Virat', 'Kohli', 30, 'Delhi', 'India');
INSERT 0 1
postgres=# insert into CRICKETERS values('Rohit', 'Sharma', 32, 'Nagpur', 'India');
INSERT 0 1
postgres=#

After inserting the records into a table you can verify its contents using the SELECT statement as shown below −

postgres=# SELECT * from CRICKETERS;
 first_name | last_name  | age | place_of_birth | country
------------+------------+-----+----------------+-------------
Shikhar     | Dhawan     | 33  | Delhi          | India
Jonathan    | Trott      |     |                | SouthAfrica
Kumara      | Sangakkara | 41  | Matale         | Srilanka
Virat       | Kohli      | 30  | Delhi          | India
Rohit       | Sharma     | 32  | Nagpur         | India
(5 rows)

Inserting Data Using Python

The cursor class of psycopg2 provides a method with name execute() method. This method accepts the query as a parameter and executes it.

Therefore, to insert data into a table in PostgreSQL using python −

  • Import psycopg2 package.

  • Create a connection object using the connect() method, by passing the user name, password, host (optional default: localhost) and, database (optional) as parameters to it.

  • Turn off the auto-commit mode by setting false as value to the attribute autocommit.

  • The cursor() method of the Connection class of the psycopg2 library returns a cursor object. Create a cursor object using this method..

  • Then, execute the INSERT statement(s) by passing it/them as a parameter to the execute() method.

Example

Following Python program creates a table with name EMPLOYEE in PostgreSQL database and inserts records into it using the execute() method −

import psycopg2

#Establishing the connection
conn = psycopg2.connect(
   database="mydb", user='postgres', password='password', host='127.0.0.1', port= '5432'
)

#Setting auto commit false
conn.autocommit = True

#Creating a cursor object using the cursor() method
cursor = conn.cursor()

# Preparing SQL queries to INSERT a record into the database.
cursor.execute('''INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) 
   VALUES ('Ramya', 'Rama priya', 27, 'F', 9000)''')
cursor.execute('''INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) 
   VALUES ('Vinay', 'Battacharya', 20, 'M', 6000)''')
cursor.execute('''INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) 
   VALUES ('Sharukh', 'Sheik', 25, 'M', 8300)''')
cursor.execute('''INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) 
   VALUES ('Sarmista', 'Sharma', 26, 'F', 10000)''')
cursor.execute('''INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) 
   VALUES ('Tripthi', 'Mishra', 24, 'F', 6000)''')

# Commit your changes in the database
conn.commit()

print("Records inserted........")

# Closing the connection
conn.close()

Output

Records inserted........

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