LeetCode 613. Shortest Distance in a Line

Table point holds the x coordinate of some points on x-axis in a plane, which are all integers.

Write a query to find the shortest distance between two points in these points.

| x   |
|-----|
| -1  |
| 0   |
| 2   |

The shortest distance is '1' obviously, which is from point '-1' to '0'. So the output is as below:

| shortest|
|---------|
| 1       |

Note: Every point is unique, which means there is no duplicates in table point.

Follow-up: What if all these points have an id and are arranged from the left most to the right most of x axis?

题目描述：求两点间的最短距离。

题目分析：利用 sql 语句查询两点间最短距离，将 x1 表和 x2 表连接起来，去除两个表的重复项即可。

MySQL 语句如下：

SELECT 
  MIN(ABS(x1.x - x2.x)) AS shortest 
FROM 
  point AS x1 
JOIN 
  point AS x2 
WHERE 
  x1.x != x2.x