[R] Help with read.csv.sql()

[Rui Barradas]

Hello,

I don't believe that what you are asking for is possible but like Bert 
suggested, you can do it after reading in the data.
You could write a convenience function to read the data, then change 
what you need to change.
Then the function would return this final object.

Rui Barradas

Às 16:43 de 18/07/2020, H escreveu:

> On 07/17/2020 09:49 PM, Bert Gunter wrote:
>> Is there some reason that you can't make the changes to the data frame (column names, as.date(), ...) *after* you have read all your data in?
>>
>> Do all your csv files use the same names and date formats?
>>
>>
>> Bert Gunter
>>
>> "The trouble with having an open mind is that people keep coming along and sticking things into it."
>> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>>
>>
>> On Fri, Jul 17, 2020 at 6:28 PM H <agents using meddatainc.com <mailto:agents using meddatainc.com>> wrote:
>>
>>      I have created a dataframe with columns that are characters, integers and numeric and with column names assigned by me. I am using read.csv.sql() to read portions of a number of large csv files into this dataframe, each csv file having a header row with columb names.
>>
>>      The problem I am having is that the csv files have header rows with column names that are slightly different from the column names I have assigned in the dataframe and it seems that when I read the csv data into the dataframe, the column names from the csv file replace the column names I chose when creating the dataframe.
>>
>>      I have been unable to figure out if it is possible to assign column names of my choosing in the read.csv.sql() function? I have tried various variations but none seem to work. I tried colClasses = c(....) but that did not work, I tried field.types = c(...) but could not get that to work either.
>>
>>      It seems that the above should be feasible but I am missing something? Does anyone know?
>>
>>      A secondary issue is that the csv files have a column with a date in mm/dd/yyyy format that I would like to make into a Date type column in my dataframe. Again, I have been unable to find a way - if at all possible - to force a conversion into a Date format when importing into the dataframe. The best I have so far is to import is a character column and then use as.Date() to later force the conversion of the dataframe column.
>>
>>      Is it possible to do this when importing using read.csv.sql()?
>>
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>>
> Yes, the files use the same column names and date format (at least as far as I know now.) I agree I could do it as you suggest above but from a purist perspective I would rather do it when importing the data using read.csv.sql(), particularly if column names and/or date format might change, or be different between different files. I am indeed selecting rows from a large number of csv files so this is entirely plausible.
>
> Has anyone been able to name columns in the read.csv.sql() call and/or force date format conversion in the call itself? The first refers to naming columns differently from what a header in the csv file may have.
>
>
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>
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