Triangle judgement

#
# Table: Triangle
# +-------------+------+
# | Column Name | Type |
# +-------------+------+
# | x           | int  |
# | y           | int  |
# | z           | int  |
# +-------------+------+
# In SQL, (x, y, z) is the primary key column for this table.
# Each row of this table contains the lengths of three line segments.
# Report for every three line segments whether they can form a triangle.
# Return the result table in any order.
# The result format is in the following example.
# Example 1:
# Input:
# Triangle table:
# +----+----+----+
# | x  | y  | z  |
# +----+----+----+
# | 13 | 15 | 30 |
# | 10 | 20 | 15 |
# +----+----+----+
# Output:
# +----+----+----+----------+
# | x  | y  | z  | triangle |
# +----+----+----+----------+
# | 13 | 15 | 30 | No       |
# | 10 | 20 | 15 | Yes      |
# +----+----+----+----------+
#

# Write your MySQL query statement below

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;