带有 HAVING 和 ORDER BY 的 Sqlite3 GROUPBY 不起作用

Question

我有一个 SQL 查询正在计算正确的输出，甚至正确地进行了排序，但是它没有执行 having 子句。难道我做错了什么？它根本没有过滤百分比。

select table1.name as theme, 
  printf("%.2f", cast(count(table2.name)as float)/(select count(table2.name) 
  from table1
  join table2
  where table1.id = table2.theme_id)*100) as percentage from table1
join table2
where table1.id = table2.theme_id
  group by table1.id
  having percentage >=5.00
  order by percentage desc;

Answer 1

问题在于，由于 printf() returns 是一个字符串，因此计算出的列 percentage 是一个字符串，您将它与 5.00 进行比较，后者是一个数字。
这种比较不能给你你所期望的，因为它不是数字之间的比较。
解决这个问题的一种方法是删除 printf() 并使用 round() 代替 returns 一个数字：

select table1.name as theme, 
  round(cast(count(table2.name)as float)/(select count(table2.name) 
  from table1
  join table2
  where table1.id = table2.theme_id)*100, 2) as percentage from table1
join table2
where table1.id = table2.theme_id
  group by table1.id
  having percentage >=5.00
  order by percentage desc;

或将 percentage 转换为 float:

having cast(percentage as float) >= 5.00

带有 HAVING 和 ORDER BY 的 Sqlite3 GROUPBY 不起作用

Sqlite3 GROUPBY with HAVING and ORDER BY not working

sqlite

group-by

nested-query

having-clause