I have a data file that contains several character variables that only consist of numbers. They need to remain character variables as some of them start with a 0 and when converting to integer/numeric, the leading zeros are cut-off. For some strange reason, when I use fwrite to save my data file as csv and then open it again with fread, the character variables that only consisted of numbers are suddenly integer variables. How can I keep R from doing this?
> str(Dataset_Master)
Classes ‘data.table’ and 'data.frame': 12178669 obs. of 4 variables:
$ Date_of_goods_arrival_at_the_customer: int 20160527 20160527 20160527...
$ Sales_document : chr "0505399186" "0505435949"...
$ Warehouse : chr "8150" "8150" "8150" "8150" ...
$ Sold_to_country : chr "DE" "DE" "DE" "DE" ...
- attr(*, ".internal.selfref")=<externalptr>
> ##Save document
> fwrite(Dataset_Master, "Dataset_Master_3.csv")
> ##Load data
> Dataset_Master <- fread("Dataset_Master_3.csv")
|--------------------------------------------------|
|==================================================|
> str(Dataset_Master)
Classes ‘data.table’ and 'data.frame': 12178669 obs. of 4 variables:
$ Date_of_goods_arrival_at_the_customer: int 20160527 20160527 20160527...
$ Sales_document : int 505399186 505435949 505435949...
$ Warehouse : int 8150 8150 8150 8150 8150 8150...
$ Sold_to_country : chr "DE" "DE" "DE" "DE" ...
- attr(*, ".internal.selfref")=<externalptr>
