OutputParameter：SQL 預存程序的輸出參數：類別產生器

OutputParameter：產生 OutputParameter 物件，該物件可針對要內嵌至 SQL Server 預存程序的函數擷取函數輸出參數的相關資訊。 這些值會成為預存程序的輸出參數。 支援的輸出參數 R 類型為 POSIXct、numeric、character、integer、logical 和 raw。 如果 R 函數針對清單的非資料框架成員傳回具名清單，則必須建立此物件

使用方式

  OutputParameter(name, type)

引數

name

字元字串，輸出參數物件的名稱。

type

輸出參數物件的 R 類型。

值

OutputParameter 物件

範例

 ## Not run:

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

 # train 2 takes a data frame with clean data and outputs a model
 # as well as the data on the basis of which the model was built
 train2 <- 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, transformFunc=NULL, transformVars=NULL)
   mm <- rxSerializeModel(mm)
   return(list(mm = mm, in_df = in_df))
 }
 # 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"))
 out1 <- OutputData("in_df")
 # create an OutputParameter object for the variable "mm" inside the return list
 out2 <- 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(train2, "spTest2", id, out1, out2,
                         filePath = ".")
 registerStoredProcedure(sp_df_op, conStr)
 result <- executeStoredProcedure(sp_df_op, connectionString = conStr)
 # Get back the linear model.
 mm <- rxUnserializeModel(result$params$op1)
## End(Not run)