mysql - MYSQL中如何对列进行排序

Question

我每行有三个字段，我想将它们连接起来，升序排列:

select * concat(field1, field2, field3) AS result
from tbl 

我的数据是:

field1, field2, field3
   7       2       9
   4       7       8
   6       3       2 

预期的结果是:

field1, field2, field3   result
  7       2       9       279
  4       7       8       478
  6       3       2       236

我该怎么做？

Answer 1

技术上使用LEAST,GREATEST函数

   SELECT field1, field2, field3,
   concat(LEAST(field1,field2,field3), 
   (field1 + field2 + field3) - (GREATEST(field1,field2,field3)+
   LEAST(field1,field2,field3)),
   GREATEST(field1,field2,field3)
   ) 
   from tbl