Question

month_column = dc.Message.date_utc.month
year_column = dc.Message.date_utc.year
message_count = fn.Count(dc.Message.id)
yearmonthname_column = year_column.concat("_").concat(month_column).concat("_").concat(dc.User.name)
yearmonth_column = year_column.concat("_").concat(month_column)
query = (dc.Message
         .select(yearmonthname_column.alias('yearmonthname'), yearmonth_column.alias('yearmonth'), dc.User.name, message_count.alias("messages_count"), year_column.alias("year"), month_column.alias("month"))
         .join(dc.User)
         .where(dc.Message.posted_in == chatId)
         .group_by(yearmonthname_column)
         .order_by(message_count.desc())
         .order_by(month_column.cast('INTEGER')) # SORTING BY MONTH
         .order_by(year_column)
         )

上面，你可以看到我的查询。这里的问题是：我希望它按month值排序，好像它是数字，但我看到的结果如下：

"1", "10", "11", "12", "2"

而不是：

"1", "2", "10", "11", "12"

按行进行按月排序：

.order_by(month_column.cast('INTEGER'))

正如您所看到的，我试图将此值转换为INTEGER，但实际上并没有改变任何内容。

这个问题是否有任何简单的解决方法？

修改

我还注意到peewee生成的最终SQL代码中没有cast。

我如何得到它：

print(query.sql())

它看起来如何：

('SELECT ((((date_part(?, "t1"."date_utc") || ?) || date_part(?, "t1"."date_utc")) || ?) || "t2"."name") AS yearmonthname, ((date_part(?, "t1"."date_utc") || ?) || date_part(?, "t1"."date_utc")) AS yearmonth, "t2"."name", Count("t1"."id") AS messages_count, date_part(?, "t1"."date_utc") AS year, date_part(?, "t1"."date_utc") AS month FROM "message" AS t1 INNER JOIN "user" AS t2 ON ("t1"."created_by_id" = "t2"."id") WHERE ("t1"."posted_in_id" = ?) GROUP BY ((((date_part(?, "t1"."date_utc") || ?) || date_part(?, "t1"."date_utc")) || ?) || "t2"."name") ORDER BY date_part(?, "t1"."date_utc")', ['year', '_', 'month', '_', 'year', '_', 'month', 'year', 'month', 220, 'year', '_', 'month', '_', 'year'])

这可能就是为什么它不起作用。有谁知道为什么会这样？

Answer 1

Title: Tales from Shakespeare (1807) Author: Shakespeare Price: 6.74 Title: The Jungle Book (1894) Author: Rudyard Kipling Price: 9.99 Title: Through the Looking-Glass (1871) Author: Lewis Carroll Price: 12.97仅适用于Peewee v3.0.0或更高版本。如果您使用的是v2.x，则必须使用.order_by(Message.month.cast('int'))中的Cast()。 .order_by(Cast(Message.month, 'int'))方法添加了this commit。

这是一个有效的代码：

cast()

PeeWee将整数值排序，就好像它们是字符串一样

1 个答案: