Mysql cross join, but without a duplicate pair?

Question

Say I have the following row in my table

table rows

  id
 63
 64
 65
 66
 67
 68

If I run the following query, I get 30 lines.

SELECT r1.id, r2,id FROM rows AS r1 CROSS JOIN rows AS r2 WHERE r1.id!=r2.id 

result:

  63 64
 65 64
 66 64
 67 64
 68 64
 64 63
 65 63
 66 63
 67 63
 68 63
 63 65
 64 65
 66 65
 67 65
 68 65
 63 66
 64 66
 65 66
 67 66
 68 66
 63 67
 64 67
 65 67
 66 67
 68 67
 63 68
 64 68
 65 68
 66 68
 67 68

how to get the following result instead of the above?

  63.64  
 63.65   
 63.66
 63.67
 63.68

 64.65
 64.66
 64.67
 64.68

 65.66
 65.67
 65.68

 66.67
 66.68

 67.68

As you can see, I do not want to receive, for example, 63.64 and 64.63.

Answer 1

Simple, only attach values ​​that exceed the current.

 select r1.id, r2,id from rows r1 cross join rows r2 where r1.id < r2.id 

Answer 2

Just add one condition. The left side will always be smaller, and then the right. This will eliminate all unwanted cases.

 select r1.id, r2,id from rows as r1 cross join rows as r2 where r1.id!=r2.id and r1.id <r2.id