我想运行sqldf（）内的下列SQL语句： select columnA, "new_column_value" as columnB, "column.C" from mytable
where columnA in ('123','456')
但是当我sqldf中运行： sqldf('select columnA, "new_column_value" as columnB, "colu
我在R中有2个数据帧，并且我想使用dataframe“y”参数对数据帧“x”执行查询。 我有这样的代码： 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
我有这样的一个表： 这是由下面的代码生成： 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:
我有一个数据框的列表，我想执行一个合并。我如何将列表中的每个元素传递给相应的sqldf语句？ 我的代码如下： 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)
我有两张客户和订单表，我想过滤出符合step1和step2需求的customer_id，而当我执行step2.5时，控制台显示 Error: Cannot pass NA to dbQuoteIdentifier()
In addition: Warning message:
In field_types[] <- field_types[names(data)] :
number