1

I need some help for a query that outputs something like this:

CityName
CITY A
CITY B
CITY C
CITY A
CITY A
CITY A
CITY C

From this example, the count of each city is: CITY A = 4 , CITY B =1 , CITY C = 2

How can I add the (nested) Count of each CityName next to it so the output looks like this:

CityName   CityCount
CITY A              4
CITY B              1
CITY C              2
CITY A              4
CITY A              4
CITY A              4
CITY C              2

Any feedback would be more than appreciated!

I have the following table with the following fields:

CitiesList --> CityName | Town | Date

An output of the table CitiesList looks like this:

CityName   |   Town      |      Date
CITY A      TOWN B      Jul 10, 2012
CITY A      TOWN D      Jul 10, 2012
CITY B      TOWN C      Jul 11, 2012
CITY C      TOWN C      Jul 11, 2012
CITY D      TOWN A      Jul 12, 2012
CITY D      TOWN C      Jul 13, 2012
CITY D      TOWN B      Jul 13, 2012
CITY E      TOWN C      Jul 13, 2012
.....

I want to add an extra field (TownCount) to this output with the number of times each TOWN appears in a time spam (Jul 10-Jul 13 in this example). The output should look like this:

CityName   |   Town      |      Date      |      TownCount
CITY A      TOWN B      Jul 10, 2012         2
CITY A      TOWN D      Jul 10, 2012         1
CITY B      TOWN C      Jul 11, 2012         4
CITY C      TOWN C      Jul 11, 2012         4
CITY D      TOWN A      Jul 12, 2012         1
CITY D      TOWN C      Jul 13, 2012         4
CITY D      TOWN B      Jul 13, 2012         2
CITY E      TOWN C      Jul 13, 2012         4
.....

4

1 に答える 1

4

使用しているシステムの種類についての詳細は提供しませんでしたが、SQL では以下を使用できます。

select t1.cityname, t2.CityCount
from yourtable t1
left join
(
    select count(*) CityCount, cityname
    from yourtable
    group by cityname
) t2
    on t1.cityname = t2.cityname

デモで SQL Fiddle を参照してください

あなたの編集に基づいて、次のことをしたいようです：

select t1.cityname, t1.town, t1.date, t2.TownCount
from yourtable t1
left join
(
    select count(*) TownCount, Town
    from yourtable
    group by Town
) t2
    on t1.town = t2.town

SQL Fiddle with Demoを参照してください

于 2012-09-18T16:21:23.383 に答える