[ MYSQL ] – 依字串 1,2,3,4,5 排序

test_string
1,2,3,4,5,6,7,8,9,10,11
select * from test order by test_string asc
排序結果：1,10,11,2,3,4,5,6,7,8,9
select * from test order by CAST(test_string AS UNSIGNED) asc
排序結果：1,2,3,4,5,6,7,8,9,10,11