search for: return_date

I have a simple query as follows: "SELECT m_id,sale_date,YEAR(sale_date),WEEK(sale_date),return_type,DATEDIFF(return_date,sale_date) AS elapsed_time FROM risk_input" I can get, and view, all the data that that query returns. The question is, sale_date is a timestamp, and I need to call split to group this data by m_id and the week in which the sale occurred. Obviously, I would normally need both YEAR and WEEK...

...he SQL below). Because of the above error, I never see about two thirds of the results that ought to be produced. At the time that the error occurs, x contains the following SQL query: SELECT m_id,sale_date,YEAR(sale_date) AS sale_year,MONTH(sale_date) AS sale_month,return_type,0.0001 + DATEDIFF(return_date,sale_date) AS elapsed_time FROM `merchants2`.`risk_input` WHERE m_id = 361 AND return_type = 1 AND DATEDIFF(return_date,sale_date) IS NOT NULL; If I execute this SQL, I find the resultset is empty. So assigning the value returned by dbGetQuery to moreinfo works ONLY if the resultset is not empty....

I must have missed something simple, but still, i don't know what. I obtained my basic data as follows: x <- sprintf("SELECT m_id,sale_date,YEAR(sale_date) AS sale_year,WEEK(sale_date) AS sale_week,return_type,0.0001 + DATEDIFF(return_date,sale_date) AS elapsed_time FROM `merchants2`.`risk_input` WHERE DATEDIFF(return_date,sale_date) IS NOT NULL") moreinfo <- dbGetQuery(con, x) I then made the data frame I want to use as follows: fun_m_id <- function(df) if (length(df$elapsed_time) > 5) { rv = fitdist(df$elapsed...