您是否正在寻找这样的东西?
select least(primary, secondary) ,greatest(primary, secondary) from yourtablegroup by least(primary, secondary) ,greatest(primary, secondary);
不论顺序如何,它将为您提供唯一/唯一的主要/次要组合一组,即{A,B}与{B,A}相同。

您是否正在寻找这样的东西?
select least(primary, secondary) ,greatest(primary, secondary) from yourtablegroup by least(primary, secondary) ,greatest(primary, secondary);
不论顺序如何,它将为您提供唯一/唯一的主要/次要组合一组,即{A,B}与{B,A}相同。