Skip to content

Passing Multiple Variable Into SQLDF Statement as parameters of function

5 messages · Gabor Grothendieck, jim holtman, scstrein

#
Hey guys,

So I'm working with a project where I manage a database within R, and I'm
developing a script/function that will automatically run my queries in R
depending on the date parameters passed in.

The problem is that when I create variables for the dates, and use those
variables in my sqldf statements, R says that there is no such column in the
dataframe (which is true!). My question is: how can I pass multiple date
variables into my sqldf statements? In particular, the sqldf is supposed to
read the date parameter as a character string (its the only way I could get
it to work). 

This is my code so far:
This passes the StartDate in correctly, but in a form where my particular
query won't pick up the date in the database. In reality, I want it to act
as the following:
Eventually, I need to have statements such as:
Thanks in advance for any feedback! :)


--
View this message in context: http://r.789695.n4.nabble.com/Passing-Multiple-Variable-Into-SQLDF-Statement-as-parameters-of-function-tp4636147.html
Sent from the R help mailing list archive at Nabble.com.
#
On Wed, Jul 11, 2012 at 11:16 AM, scstrein <scstrein at ncsu.edu> wrote:
See example 5 on the sqldf home page;
http://code.google.com/p/sqldf/#Example_5._Insert_Variables
#
You have to explicitly add the quotes:

 Example=paste0("select * from LibDB where Date_Entered
='",as.character(StartDate), "'") # notice the single quotes within
the double quotes

        
On Wed, Jul 11, 2012 at 11:16 AM, scstrein <scstrein at ncsu.edu> wrote:

  
    
#
Thanks! For some reason, example 5 in that documentation doesn't work for me. 
It runs the query, but I'm getting zero results.  If I substitute the
variable with the actual value, I do get the results I want.  Is there a
reason for this? 

--
View this message in context: http://r.789695.n4.nabble.com/Passing-Multiple-Variable-Into-SQLDF-Statement-as-parameters-of-function-tp4636147p4636300.html
Sent from the R help mailing list archive at Nabble.com.
#
On Thu, Jul 12, 2012 at 9:41 AM, scstrein <scstrein at ncsu.edu> wrote:
Read the troubleshooting section and if that still does not address
your problem then contact me.
http://code.google.com/p/sqldf/#Troubleshooting