InputData:SQL 存储过程的输入数据:类生成器
InputData
:生成一个 InputData 对象,该对象捕获有关作为数据帧的输入参数的信息。
在执行给定查询时需要填充数据帧。
创建嵌入 R 函数采用数据帧输入参数存储过程时,此对象是必需的。
用法
InputData(name, defaultQuery = NULL, query = NULL)
参数
name
一个字符串,即提供给 StoredProcedure 的 R 函数中数据输入参数的名称。
defaultQuery
一个字符串,指定在执行存储过程中未提供其他查询时将检索数据的默认查询。 必须是简单的 SELECT 查询。
query
一个字符串,指定将用于在存储过程的下一次运行中检索数据的查询。
值
InputData 对象
示例
## 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 InputData 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)