问题
I have a sql query below that works just fine.
Select * from dbo.Employee where StartDate between '08/01/2014' and '08/31/2014' order by StartDate
I am modifying this query such that it takes date input from shiny UI (daterange) .
sqlQuery(myconn, paste("Select * from dbo.Employee where StartTime between", "'as.character(input$daterange[1])'", "and", "'as.character(input$daterange[2])'", "order by StartTime"))
I get an error
[1,] "22007 241 [Microsoft][SQL Server Native Client 10.0][SQL Server]Conversion failed when converting date and/or time from character string."
[,2] "[RODBC] ERROR: Could not SQLExecDirect ' Select * from..... Where StartDate between 'as.character(input$daterange[1])' and 'as.character(input$daterange[2])' order by StartDate '"
Not sure how to fix this query such that it takes date input from shiny UI, need help.
回答1:
I use sub function to do that, by simply using regular expressions like so:
my_date1 <- "08/01/2014"
my_date2 <- "08/31/2014"
my_query <- 'Select * from dbo.Employee where StartDate between DATE1 and DATE2 order by StartDate'
my_query <- sub("DATE1",my_date1,my_query);my_query <- sub("DATE2",my_date2,my_query)
# the result of your query is below
noquote(my_query)
# if you want the quotes for dates leave them there
my_query <- 'Select * from dbo.Employee where StartDate between "DATE1" and "DATE2" order by StartDate'
my_query <- sub("DATE1",my_date1,my_query);my_query <- sub("DATE2",my_date2,my_query)
# the result of your query is below
noquote(my_query)
# Now sub the inputs into those variables like so
my_query <- 'Select * from dbo.Employee where StartDate between DATE1 and DATE2 order by StartDate'
my_query <- sub("DATE1",input$daterange[1],my_query);my_query <- sub("DATE2",input$daterange[2],my_query)
noquote(my_query)
来源：https://stackoverflow.com/questions/28934967/r-shiny-date-range-input-to-sql-query