Python PostgreSQL Select From

Select From a Table

FILE: select_from_tab.py

import psycopg2
conn = psycopg2.connect(database = "kwikl3arn", user = "postgres", password = "post123", host = "localhost", port = "5432")
conn.autocommit = True
print ("Opened database successfully")

cur = conn.cursor()

cur.execute("select * from customers")
rows = cur.fetchall()
for row in rows:
     print(row)

conn.close()

RUN:

C:\Users\Your Name>python select_from_tab.py

Opened database successfully
('John', 'Highway 21')
('naruto', 'japan')
('morning star', 'LA')
('Amy', 'apple')

Selecting Columns

 FILE: select_one_from_tab.py

import psycopg2
conn = psycopg2.connect(database = "kwikl3arn", user = "postgres", password = "post123", host = "localhost", port = "5432")
conn.autocommit = True
print ("Opened database successfully")

cur = conn.cursor()

cur.execute("select name from customers")
rows = cur.fetchall()
for row in rows:
     print(row)

conn.close()

RUN:

C:\Users\Your Name>python select_one_from_tab.py

Opened database successfully
('John')
('naruto')
('morning star')
('Amy')

Using the fetchone() Method

If you are only interested in one row, you can use the fetchone() method.

The fetchone() method will return the first row of the result:

 FILE: select_one_from_tab1.py

import psycopg2
conn = psycopg2.connect(database = "kwikl3arn", user = "postgres", password = "post123", host = "localhost", port = "5432")
conn.autocommit = True
print ("Opened database successfully")

cur = conn.cursor()

cur.execute("select * from customers")
rows = cur.fetchone()

print(rows)

conn.close()

RUN:

C:\Users\Your Name>python select_one_from_tab1.py

Opened database successfully
('John', 'Highway 21')