This video is the fourth part of our series on SQL interview questions and answers. This series is specifically designed for people targeting jobs as data analysts, data scientists, data engineers, and business analysts.
In this video, I have explained how to delete duplicate entries in our database using two types of methods
1) Fetch unique values using the DISTINCT keyword and store the output in a table
2) Add a new temporary column using the ALTER TABLE command and use the column to remove the duplicate entries
Use the below the commands to create your own database and table:
CREATE DATABASE THEMLMINE;
USE THEMLMINE;
CREATE TABLE emp
(
emp_id INT,
name varchar(20),
age INT,
salary FLOAT
);
INSERT INTO emp VALUES
(102, 'Aviral', 24, 20000),
(103, 'Arohi', 28, 350000),
(104, 'James',35, 120000),
(102, 'Aviral', 24, 20000);
You can download the final script from here: drive.google.com/file/d/1NkQF...
Learn SQL from scratch: • SQL Tutorial for begin...
Instagram: / the_ml_mine
Timestamps:
00:00 Introduction
00:06 Interview question
01:18 MySQL workbench
02:50 Method 1 - Solution 1 (using DISTINCT keyword)
05:05 Method 1 - Solution 2 (using DISTINCT keyword)
07:37 Method 2 (adding a temporary column)
14:09 Summary
14:16 Outro
14:24 Call to action
Music credits:
Education - upbeat positive (short ver.) by AudioCoffee -- freesound.org/s/724628/
-- License: Attribution NonCommercial 4.0