InputData: Input Data for SQL Stored Procedure: Class Generator

Article
04/15/2024

InputData: generates an InputData Object that captures the information about the input parameter that is a data frame. The data frame needs to be populated upon the execution a given query. This object is necessary for creation of stored procedures in which the embedded R function takes in a data frame input parameter.

Usage

  InputData(name, defaultQuery = NULL, query = NULL)

Arguments

`name`

A character string, the name of the data input parameter into the R function supplied to StoredProcedure.

`defaultQuery`

A character string specifying the default query that will retrieve the data if a different query is not provided at the time of the execution of the stored procedure. Must be a simple SELECT query.

`query`

A character string specifying the query that will be used to retrieve the data in the next run of the stored procedure.

Value

InputData Object

Examples


 ## Not run:

 # See ?StoredProcedure for creating the "cleandata" table.

 # train 1 takes a data frame with clean data and outputs a model
 train1 <- function(in_df) {
   in_df[,"DayOfWeek"] <- factor(in_df[,"DayOfWeek"], levels=c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"))
   # The model formula
   formula <- ArrDelay ~ CRSDepTime + DayOfWeek + CRSDepHour:DayOfWeek
   # Train the model
   rxSetComputeContext("local")
   mm <- rxLinMod(formula, data=in_df)
   mm <- rxSerializeModel(mm)

   return(list("mm" = mm))
 }
 # create InpuData Object for an input parameter that is a data frame
 # note: if the input parameter is not a data frame use InputParameter object
 id <- InputData(name = "in_df",
                defaultQuery = paste0("select top 10000 ArrDelay,CRSDepTime,",
                                      "DayOfWeek,CRSDepHour from cleanData"))
 # create an OutputParameter object for the variable inside the return list
 # note: if that variable is a data frame use OutputData object
 out <- OutputParameter("mm", "raw")

 # connections string
 conStr <- paste0("Driver={ODBC Driver 13 for SQL Server};Server=.;Database=RevoTestDB;",
                  "Trusted_Connection=Yes;")
 # create the stored procedure object
 sp_df_op <- StoredProcedure("train1", "spTest1", id, out,
                        filePath = ".")
 # register the stored procedure with the database
 registerStoredProcedure(sp_df_op, conStr)

 # execute the stored procedure, note: non-data frame variables inside the
 # return list are not returned to R. However, if the execution is not successful
 # the error will be displayed
 model <- executeStoredProcedure(sp_df_op, connectionString = conStr)
 # get the linear model
 mm <- rxUnserializeModel(model$params$op1)
## End(Not run)

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