SQLDF如何添加新的vetors？

Question

看到我有data.frame這樣的：

str(veh) 
$VEHAGE int 3 6 35 35 5 3 7 4 5 1 ... 
$VEHTYPE int 2 1 3 1 2 3 1 4 2 3 ... 

然後我跑

a<-sqldf("SELECT VEHAGE, COUNT(VEHAGE) as count1 
          FROM veh 
          WHERE VEHTYPE==1 
          GROUP BY VEHAGE") 


a<-sqldf("SELECT VEHAGE, COUNT(VEHAGE) as count234 
          FROM veh 
          WHERE VEHTYPE==2|3|4 
          GROUP BY VEHAGE") 

我得到的結果是這樣

head(a) 
    VEHAGE count234 
1  -9  92 
2  1  79 
3  2 164 
4  3 212 
5  4 260 
6  5 199 

我在這種情況下失去COUNT1。但我想要一個像這樣的頭（一）

VEHAGE count1 count234 
1  -9  92 510 
2  1  79 844 
3  2 164 123 
4  3 212 123 
5  4 260 100 
6  5 199 100 

任何想法？提前致謝！

Answer 1

我想你正在尋找這樣的：

# first query 
a <- sqldf("SELECT VEHAGE, COUNT(VEHAGE) as count1 
          FROM veh 
          WHERE VEHTYPE==1 
          GROUP BY VEHAGE") 

# second query 
b <- sqldf("SELECT VEHAGE, COUNT(VEHAGE) as count234 
          FROM veh 
          WHERE VEHTYPE IN (2, 3, 4) 
          GROUP BY VEHAGE") 

# combine 
a <- sqldf("SELECT * 
      FROM a JOIN b 
      USING (VEHAGE)") 

Answer 2

試着這麼做：

a<-sqldf(
"SELECT VEHAGE, 
    SUM(if(VEHTYPE==1, 1, 0)) as count1, 
    SUM(if(VEHTYPE==2|3|4, 1, 0)) as count234 
    FROM veh 
    GROUP BY VEHAGE") 

雖然聲明，我不熟悉sqldf語法，但像這樣的工作， MySQL（儘管在MySQL ==2|3|4中必須是in(2, 3, 4)）。

此外，您可能需要添加諸如HAVING count1 | count234之類的東西來擺脫VEHAGE，並且這些類別中沒有車輛。