SQL – DELETE Statement
In the DELETE statement in SQL, it deletes the existing records from the table. It is operated using a condition in the WHERE clause. The condition in the where clause determines which records are going to be deleted. The WHERE clause is necessary because if the clause gets omitted, then all the records from the table get deleted as the WHERE clause determines which record needs to be deleted.
- Syntax of DELETE statement –
DELETE FROM table_name WHERE condition ;
Demo Table –
Sales Order Table
|
Order date |
Region |
Rep |
Item |
Units |
Unit Cost |
Total |
|
2021-01-23 00:00:00.000 |
Central |
Kivell |
Binder |
50 |
19.99 |
999.5 |
|
2021-02-26 00:00:00.000 |
Central |
Gill |
Pen |
27 |
19.99 |
539.73 |
|
2021-04-01 00:00:00.000 |
East |
Jones |
Binder |
60 |
4.99 |
299.4 |
|
2021-06-08 00:00:00.000 |
East |
Jones |
Binder |
60 |
8.99 |
539.4 |
|
2021-07-12 00:00:00.000 |
East |
Howard |
Binder |
29 |
1.99 |
57.71 |
|
2021-07-29 00:00:00.000 |
East |
Parent |
Binder |
81 |
19.99 |
1619.19 |
|
2021-09-01 00:00:00.000 |
Central |
Smith |
Desk |
2 |
125 |
250 |
|
2021-09-18 00:00:00.000 |
East |
Jones |
Pen Set |
16 |
15.99 |
255.84 |
|
2021-10-05 00:00:00.000 |
Central |
Morgan |
Binder |
28 |
8.99 |
251.72 |
|
2021-10-22 00:00:00.000 |
East |
Jones |
Pen |
64 |
8.99 |
575.36 |
Example – Consider the Sales Order table of the Customer database where we want to DELETE those records that have an order item as a pencil.
DELETE FROM [dbo].[SalesOrders] WHERE Item = 'Pen';
This output is the small section of the output by executing the above query –
|
Order date |
Region |
Rep |
Item |
Units |
Unit_cost |
Total |
|
2021-01-23 00:00:00.000 |
Central |
Kivell |
Binder |
50 |
19.99 |
999.5 |
|
2021-04-01 00:00:00.000 |
East |
Jones |
Binder |
60 |
4.99 |
299.4 |
|
2021-06-08 00:00:00.000 |
East |
Jones |
Binder |
60 |
8.99 |
539.4 |
|
2021-07-12 00:00:00.000 |
East |
Howard |
Binder |
29 |
1.99 |
57.71 |
|
2021-07-29 00:00:00.000 |
East |
Parent |
Binder |
81 |
19.99 |
1619.19 |
|
2021-09-01 00:00:00.000 |
Central |
Smith |
Desk |
2 |
125 |
250 |
|
2021-09-18 00:00:00.000 |
East |
Jones |
Pen Set |
16 |
15.99 |
255.84 |
|
2021-10-05 00:00:00.000 |
Central |
Morgan |
Binder |
28 |
8.99 |
251.72 |
|
2021-11-25 00:00:00.000 |
Central |
Kivell |
Pen Set |
96 |
4.99 |
479.04 |
|
2021-12-29 00:00:00.000 |
East |
Parent |
Pen Set |
74 |
15.99 |
1183.26 |
As we can see in the results, the records that have “Pen” as their item got deleted, But the whole record didn’t get deleted as we had a condition in the WHERE clause.
Other SQL topics to check out:
- How to write SQL Select Statements
- Introduction to SQL for Data Scientists
- What is RDBMS (Relational Database Management System)?
- SQL WHERE Clause
Follow us on Twitter, Facebook, Linkedin, and Tableau Public to stay updated with our latest blog and what’s new in Tableau.
If you are looking forward to getting your data pipeline built and setting up the dashboard for business intelligence, book a call now from here.
#analytics #data #business #artificialintelligence #machinelearning #startup #deeplearning #deeplearning #datascience #ai #growth #dataanalytics #india #datascientist #powerbi #dataanalysis #tableau #SQL #businessanalytics #businessanalyst #businessandmanagement #dataanalyst #businessanalysis #analyst #analysis #powerbideveloper #powerbidesktop #letsviz
