Download our e-book of Introduction To Python

Top Discussion

How can I write Python code to change a date string from "mm/dd/yy hh: mm" format to "YYYY-MM-DD HH: mm" format? Exception Type: JSONDecodeError at /update/ Exception Value: Expecting value: line 1 column 1 (char 0) Someone guide please. How to store the name of IV in a list which show non linear behavior ?.......How to understand data is linear or non linear ? 'collections.OrderedDict' object has no attribute 'status_code' What is the difference between a module and a package in Python? How can i use pyspark to parallelize a file's payload How to leave/exit/deactivate a Python virtualenvironment Join Discussion

Top Courses

Webinars

Generative AI Journey in Data Science

Dec 6th (8:00 PM) 2014 Registered

More webinars

Python PostgreSQL - Drop Table

Neha Kumawat

2 years ago

Python PostgreSQL - Drop Table | Insideaiml

Table of Content

Syntax

Example

Removing an Entire Table Using Python

Output

In this article, we will try to see one of the most important topics i.e., How we can drop table in PostgreSQL using python.

You can drop a table from PostgreSQL database using the DROP TABLE statement.

Syntax

Following is the syntax of the DROP TABLE statement in PostgreSQL −


DROP TABLE table_name;

Example

Assume we have created two tables with name CRICKETERS and EMPLOYEES using the following queries −


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=#
postgres=# CREATE TABLE EMPLOYEE(
   FIRST_NAME CHAR(20) NOT NULL, LAST_NAME CHAR(20), 
   AGE INT, SEX CHAR(1), INCOME FLOAT
);
CREATE TABLE
postgres=#

Now if you verify the list of tables using the “\dt” command, you can see the above created tables as −


postgres=# \dt;
            List of relations
 Schema | Name       | Type  | Owner
--------+------------+-------+----------
 public | cricketers | table | postgres
 public | employee   | table | postgres
(2 rows)
postgres=#

Following statement deletes the table named Employee from the database −


postgres=# DROP table employee;
DROP TABLE

Since you have deleted the Employee table, if you retrieve the list of tables again, you can observe only one table in it.


postgres=# \dt;
            List of relations
Schema  | Name       | Type  | Owner
--------+------------+-------+----------
public  | cricketers | table | postgres
(1 row)


postgres=#

If you try to delete the Employee table again, since you have already deleted it, you will get an error saying “table does not exist” as shown below −


postgres=# DROP table employee;
ERROR: table "employee" does not exist
postgres=#

To resolve this, you can use the IF EXISTS clause along with the DELTE statement. This removes the table if it exists else skips the DLETE operation.


postgres=# DROP table IF EXISTS employee;
NOTICE: table "employee" does not exist, skipping
DROP TABLE
postgres=#

Removing an Entire Table Using Python

You can drop a table whenever you need to, using the DROP statement. But you need to be very careful while deleting any existing table because the data lost will not be recovered after deleting a table.


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()

#Doping EMPLOYEE table if already exists
cursor.execute("DROP TABLE emp")
print("Table dropped... ")

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

#Closing the connection
conn.close()

Output


Table dropped...

I hope you enjoyed reading this article and finally, you came to know about Python PostgreSQL - Drop Table.

For more such blogs/courses on data science, machine learning, artificial intelligence and emerging new technologies do visit us at InsideAIML.

Thanks for reading…

Happy Learning…

Related Blog