我想運行sqldf（）內的下列SQL語句： select columnA, "new_column_value" as columnB, "column.C" from mytable
where columnA in ('123','456')
但是當我sqldf中運行： sqldf('select columnA, "new_column_value" as columnB, "colu
我在R中有2個數據幀，並且我想使用dataframe「y」參數對數據幀「x」執行查詢。 我有這樣的代碼： x <- c('The book is on the table','I hear birds outside','The electricity
came back')
x <- data.frame(x)
colnames(x) <- c('text')
x
y <- c('b
我有這樣的一個表： 這是由下面的代碼生成： id <- c("1","2","1","2","1","1")
status <- c("open","open","closed","closed","open","closed")
date <- c("11-10-2017 15:10","10-10-2017 12:10","12-10-2017 22:10","13-10-2017 06:
我有一個數據框的列表，我想執行一個合併。我如何將列表中的每個元素傳遞給相應的sqldf語句？ 我的代碼如下： require(sqldf)
a <- data.frame(ID=c("a","b","c","d","a","a"),num=1:6,num2=2:7)
b <- data.frame(ID=c("d","a","a","a","b","c"),num=6:1,num2=7:2)
我有兩張客戶和訂單表，我想過濾出符合step1和step2需求的customer_id，而當我執行step2.5時，控制檯顯示 Error: Cannot pass NA to dbQuoteIdentifier()
In addition: Warning message:
In field_types[] <- field_types[names(data)] :
number