A pupil Tim gets homework to identify whether three line segments could possibly form a triangle.
However, this assignment is very heavy because there are hundreds of records to calculate.
Could you help Tim by writing a query to judge whether these three sides can form a triangle, assuming table triangle
holds the length of the three sides x, y and z.
| x | y | z | |----|----|----| | 13 | 15 | 30 | | 10 | 20 | 15 |
For the sample data above, your query should return the follow result:
| x | y | z | triangle | |----|----|----|----------| | 13 | 15 | 30 | No | | 10 | 20 | 15 | Yes |
Code
1) use IF
SELECT*, if (x+y>z and x+z>y and y+z>x, "Yes","No") as triangle FROM triangle
2) use case
SELECT x, y, z, CASE WHEN x + y > z AND x + z > y AND y + z > x THEN ‘Yes‘ ELSE ‘No‘ END AS ‘triangle‘ FROM triangle
原文地址:https://www.cnblogs.com/Johnsonxiong/p/9551781.html
时间: 2024-10-14 09:13:37