SQL語句分類變量計數與百分比統計

select reviewAverage,count(reviewAverage) as count from table_nm group by reviewAverage having reviewAverage is not null order by reviewAverage

簡單的查詢語句大家都比較容易的了解。select 字段A,count(A) as count from 表名 group by 字段A order by count。但是想要百分比出現在後面，需要子查詢語句。

*select reviewAverage,count(reviewAverage) as count,concat(round(count(reviewAverage)/(select count(*) from 表名)100,2),’’,’%’) as per from 表名 group by reviewAverage having reviewAverage is not null order by reviewAverage

百分比=count/sum

count(字段)-----------計數count

select count() from 表名 ------- 求出sum

count(字段)/(select count() from 表名)---------百分比

round(百分比100，2）-------保留兩位小數

concat(round(百分比100，2），‘’，’%’)-------轉換成百分比

隻需要把查詢結果：concat(round(count(reviewAverage)/(select count() from 表名)100,2),’’,’%’) as per 當成一個字段即可。

END

有問題，歡迎留言。

每日更新(sql,R,python,databricks,sqlserver),感謝關注！！！