[R] Passing arguments to SQL Query in R

[R. Michael Weylandt]

On Thu, Jul 26, 2012 at 3:59 AM, guruappa <guruappa at gmail.com> wrote:
> Hello all,
>
> I am a newbie at R, with some experience in PERL.
>
> I have a database table that contains the following data:
> Name      | Score
> ======= | =====
> Sachin T  | 25
> Sachin T  | 53
> Sachin T  | 57
> Sachin T  | 34
> Rahul D   | 38
> Rahul D   | 31
> Rahul D   | 53
> Ricky P   |  7
> Ricky P   | 45
> Ricky P   | 27
> Ricky P   | 17
> Ricky P   | 86
> Ricky P   | 48
> Jacques K | 23
> Jacques K | 86
> Jacques K | 32
>
> I want the summary data as below:
>
> Name | Avg Score
> Jacques K|47.00
> Rahul D|40.67
> Ricky P|38.33
> Sachin T|42.25
>
> Currently, I am trying to pass the name of the person as an argument in a
> sql query by breaking the query into parts, and then concatenating the query
> string.  Of course, the scheme is not working.
>
> I want a query as below:
> SELECT NAME, SCORE FROM PLAYER_SCORE_TBL where NAME = ?
>
> Then I can pass the parameters like we do in PERL.
>
> If there is an alternative to the whole scheme, that would be wonderful.  a
> way that would just take the whole table, and provide pivot table like
> solution.

Many, but I'll give one:

with(DataFrameName, tapply(Score, Name, mean))

also aggregate(), ave(), and many others.

Off topic: you might look at the sqldf package to do sql-form queries
on R objects.

Best,
Michael

>
> Thanks in advance,
> Guruppa Padsali.
>
>
>
>
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