with x as (

select '20190101' as order1,'A' as goods from dual

union all

select '20190101' as order1,'B' as goods from dual

union all

select '20190101' as order1,'C' as goods from dual

union all

select '20190102' as order1,'A' as goods from dual

union all

select '20190102' as order1,'C' as goods from dual

union all

select '20190103' as order1,'C' as goods from dual

union all

select '20190103' as order1,'D' as goods from dual

)

SELECT y.goods1, y.goods2, COUNT(DISTINCT y1.order1) as js

FROM(

    SELECT A.goods as goods1, B.goods as goods2

    FROM (SELECT DISTINCT goods FROM x) A,

        (SELECT DISTINCT goods FROM x) B

    WHERE A.goods < B.goods

) y  INNER JOIN x y1 ON y1.goods = y.goods1

WHERE EXISTS(SELECT * FROM x y2  WHERE y2.order1 = y1.order1   AND y2.goods = y.goods2)

GROUP BY y.goods1, y.goods2;

你在不是同一销售单啊，销售单号都不一样，是不是要得到所有销售单中出现次数最多的商品

其实返过来 商品分组 然后个数最多的就好了啊 

常用函数集合插件-http://help.finereport.com/doc-view-1493.html看一下这个帮助文档中的函数：MathFrequency函数

统计单词出现的次数和频率。

MathFrequency([1, 3, 2, 4, 2], 3)返回1，表示数组中3出现了一次，

如果给定了第三个参数，则返回0.2，表示3出现的频率为0.2。即：MathFrequency([1, 3, 2, 4, 2], 3,3)返回0.2