Not all data read in from SQL database to R - sql

Question

I am creating a Shiny app and have been using data from Microsoft SQL Server Management Studio by creating my table with the query below, saving it as a CSV, and reading it in with
alldata<-read.csv(file1$datapath, fileEncoding = "UTF-8-BOM")
with the above code in my server function and the below code in my ui function
fileInput("file1", "Choose CSV File", accept=".csv")
Using this code, I have been able to manipulate the all the data (creating tables and plots) from the CSV successfully. I wanted to try directly obtaining the data from the SQL server when my app loads instead of going into SQL, executing the query, saving the data, and then loading it into my app. I tried the below code, and it sort of works. For example, the variable CODE has 30 levels, all of which are represented and able to be manipulated when I read the data in with the CSV, but only 23 are represented and manipulated when I run the below code. Is there a specific reason this may be happening. I tried running the SQL code along with the code to make my datatables in base R, instead of shiny to see if I could spot something specific not being read in correctly, but it all works perfectly when I read it in line by line
library(RODBCext)
dbhandle<-odbcDriverConnect('driver={SQL Server}; server=myserver.com;
database=mydb; trusted_connection=true')
query<-"SELECT CAST(r.DATE_COMPLETED AS DATE)[DATE]
, res.CODE
, r.TYPE
, r.LOCATION
, res.OPERATION
, res.UNIT
FROM
mydb.RECORD r
LEFT OUTER JOIN mydb.RESULT res
ON r.AMSN = res.AMSN
and r.unit = res.unit
where r.STATUS = 'C'
and res.CODE like '%ABC-%'"
auditdata<-sqlExecute(channel=dbhandle, query=query, fetch=TRUE, stringsAsFactors=FALSE)
odbcClose(dbhandle)
*I only want the complete data set loaded once per Shiny session, so I currently have this outside of the server function in my server.R file.

Answer 1

Try adding 'believeNRows=FALSE' to your SQLExecute call. RODBC doesn't return the full query without this parameter.
auditdata<-sqlExecute(channel=dbhandle, query=query, fetch=TRUE, stringsAsFactors=FALSE, believeNRows=FALSE)