板球赛程表匹配SQL查询

Question

I have a table with list of countries as shown below. Every country will play against all countries in the list. I need a query to display the list of opponent countries in format (country1, country2) for all the possible matches without repetitions. eg c1 & c2 will play against each other. Display list should not have c2 & c1 (repetition)

CtryName
---
c1
c2
c3
c4
c5

It's an interview question. I have no idea how to get expected results. Please help me by a simple query to display expected results.

Answer 1

Try like this:

select t1.c teamA, t2.c teamB
  from test t1,
       test t2
 where t1.c < t2.c
order by t1.c, t2.c

I named the table as test and the country column as c .

See it here on fiddle: http://sqlfiddle.com/#!6/9124f/2