# HackerRank: [SQL Advanced Select] (1/5) TYPE OF TRIANGLE | case when in SQL

I started studying SQL from a very famous site - HackerRank. Here I will try to provide multiple approaches & solutions to the same problem. It will help you learn and understand SQL in a better way.

Please make use of my blog posts for learning purpose only and feel free to ask your questions in the comment box below in case of any doubt.

Click Here for the previous blog-post in the series.

Recommended SQL Courses:

**SQL Problem Statement:**

Write a query identifying the type of each record in the **TRIANGLES **table using its three side lengths. Output one of the following statements for each record in the table:

**Equilateral:**It's a triangle with**3**sides of equal length.**Isosceles:**It's a triangle with**2**sides of equal length.**Scalene:**It's a triangle with**3**sides of differing lengths.**Not A Triangle:**The given values of A, B, and C don't form a triangle.

**Input Format:**

The **TRIANGLES** table is described as follows:

TRIANGLES Columns |

**Sample Input:**

**Sample Output:**

**Explanation:**

- Values in the tuple (20,20,23) form an
**Isosceles**triangle, because A=B. - Values in the tuple (20,20,20) form an
**Equilateral**triangle, because A=B=C. - Values in the tuple (20,21,22) form a
**Scalene**triangle, because A!=B!=C. - Values in the tuple (13,14,30)
**cannot form a triangle**because the combined value of sides A and B is not larger than that of side C.

**Solution-1: Using 'AND', 'OR' Clauses(MySQL Query):**

**NOTE:**

- Here, the Sequence of When conditions are very important. If you move down the When condition corresponding to '
**Not A Trangle**' at the bottom, the query__will not work as expected__.

### Solution-2: Using '&', '|' Operators (MySQL Query):

**NOTE:**

- Here, the Sequence of When conditions are very important. If you move down the When condition corresponding to '
**Not A Trangle**' at the bottom, the query__will not work as expected__.

**Sample Output:**

--------------------------------------------------------------------------------

**Click here**to see solutions for all

**Machine Learning**Coursera Assignments.

&

**Click here**to see more codes for

**Raspberry Pi 3**and similar Family.

&

**Click here**to see more codes for

**NodeMCU ESP8266**and similar Family.

&

**Click here**to see more codes for

**Arduino Mega (ATMega 2560)**and similar Family.

Feel free to ask doubts in the comment section. I will try my best to answer it.

If you find this helpful by any mean like, comment and share the post.

This is the simplest way to encourage me to keep doing such work.

Thanks & Regards,

**-Akshay P Daga**

## No comments