安装了ORE, 连接Oracle数据库, NEW_FLat1 是该数据库的一个表
> d1 <- ore.get("NEW_FLat1")
想要把d1的后13列改成字符格式,做了如下尝试:
> d1[, 2:14]<- by(d1[, 2:14], as.ore.character)
Error in function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE, :
cannot coerce class 'Standard Generic' into an 'ore.frame'
> d1[, 2:14]<- by(d1[, 2:14], as.character)
Error in function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE, :
cannot coerce class 'function' into an 'ore.frame'
> d1[, 2:14] <- as.ore.character(d1[, 2:14])
Error in '[<-.data.frame'('*tmp*', , i, value =character(0)) :
new columns would leave holes after existing columns
In addition: Warning message:
In '[<-.data.frame'('*tmp*', , i, value =character(0)) :
Setting class(x) to NULL; result will no longer be an S4 object
> d1[, 2:14] <- as.character(d1[, 2:14])
Error in '[<-.data.frame'('*tmp*', , i, value =character(0)) :
new columns would leave holes after existing columns
In addition: Warning message:
In '[<-.data.frame'('*tmp*', , i, value =character(0)) :
Setting class(x) to NULL; result will no longer be an S4 object
> d1[, 2] <- as.character(d1[, 2])
Error in '[<-.data.frame'('*tmp*', , 2, value =character(0)) :
new columns would leave holes after existing columns
In addition: Warning message:
In '[<-.data.frame'('*tmp*', , 2, value =character(0)) :
Setting class(x) to NULL; result will no longer be an S4 object
然后查看了d1,
> dim(d1)
[1] 2227868 14
> str(d1[,2])
Formal class 'ore.factor' [package "OREbase"] with 8你slots
..@ .Data : raw(0)
..@ dataQry : Named chr [1:2] "( select \ "RowID\" NAME001, \ "RowID\" VAL001, \ "NAME\" VAL002, ......
.. .. - attr(*, "names") = chr [1:2] "803_227" "803_286"
..@ dataObj : chr "803_286"
..@ sqlName : chr "\"RowID\""
..@ sqlValue : chr "\"NAME\""
..@ sqlTable : chr "\"XXX\".\ "NEW_FLAT1\""
..@ sqlPred : chr ""
..@ exRef : list()
以前曾经用ore.pull(),然后再用R. 可现在的表太大, 取出来太慢, 想直接用ORE,希望高手指点一下...
拜谢