显示美国的独特温度值

Question

我想做一些类似于我在 SQL 中在 R（下方）中所做的事情：

clim_data %>%
select(Year, AverageTemperature, State) %>%
group_by(Year,State) %>%
summarize(value = mean(AverageTemperature), .groups = 'drop') -> clim_data3

colnames(clim_data3)[2] <- "region" 
clim_data3$region<-tolower(clim_data3$region)

clim_data3 %>%
filter(Year==1900) -> clim_data1900
clim_data1900<-clim_data1900[,2:3]

此代码的输出如下所示：

region  value
<chr>   <dbl>
alabama 17.059167
alaska  -5.146500
arizona 15.742917
arkansas    15.893417
california  14.51575

到目前为止，在 SQL 中，我已经设法使用以下代码输出单个状态：

select distinct year, round(avg(AverageTemperature) over (partition by year),2) as avgTemp, Country, State
from dbo.landTemps
where AverageTemperature is not null and 
    Country = 'United States' and 
    state = 'Alabama' and
    year = 1900

输出如下所示：

year    avgTemp   Country        State
1900    17.06   United States   Alabama

但是，我无法获得每个州的唯一 avgTemp。当我将它带到多个状态时，我会为该查询中的所有状态获得相同的 avgTemp。所以如果我运行这样的查询：

select distinct year, round(avg(AverageTemperature) over (partition by year),2) as avgTemp, Country, State
from dbo.landTemps
where AverageTemperature is not null and 
    Country = 'United States' and 
    state like 'A%' and
    year = 1900

我得到了这些州的平均值。

year    avgTemp   Country        State
1900    15.15   United States   Alaska
1900    15.15   United States   Arizona
1900    15.15   United States   Arkansas
1900    15.15   United States   Alabama

我假设我需要编写某种子查询来遍历每个状态并给出 avgTemp。我也尝试对状态进行分区，但它没有给我想要的东西。我的总体目标是打印出给定年份的每个州的 avgTemp。

数据集包含每年和州的多个值：

select year, round(avg(AverageTemperature) over (partition by year),2) as avgTemp, Country, State
from dbo.landTemps
where AverageTemperature is not null and 
    Country = 'United States' and 
    state like 'A%' and
    year = 1900

output: 
year    avgTemp  Country         State
1900    15.15   United States   Alabama
1900    15.15   United States   Alabama
1900    15.15   United States   Alabama
1900    15.15   United States   Alabama

阿拉巴马州条目较多，下方还有其他 'A' 州，因此我认为必须使用不同的年份。我只是卡住并将单个状态扩展为多个状态，而没有取查询中所有状态的平均值。数据集可以在这里找到：https://www.kaggle.com/berkeleyearth/climate-change-earth-surface-temperature-data?select=GlobalLandTemperaturesByState.csv

感谢您的帮助！

Answer 1

由于您要查找每个州的平均温度，因此您应该将州列添加到按子句分区。

尝试：

select year, round(avg(AverageTemperature) over (partition by year,State),2) as avgTemp, Country, State
from dbo.landTemps
where AverageTemperature is not null and 
    Country = 'United States' and 
    state like 'A%' and
    year = 1900

Answer 2

您需要 GROUP BY 和常规聚合函数 AVG()，AVG() over (partition by...) 是一个分析函数而不是常规聚合。 EG

select  Country, State, year, avg(AverageTemperature) as avgTemp
from dbo.landTemps
where AverageTemperature is not null
group by Country, State, year

显示美国的独特温度值

Displaying Unique Temperature Values for the US

sql

sql-server

subquery

partition-by