Multiple Data Sets And SQL Server R Services

Kevin Feasel

2017-11-03

R

Robert Sheldon has a workaround for SQL Server R Services’s limitation of a single input data set:

Despite the ease with which you can run an R script, the sp_execute_external_script stored procedure has an important limitation. You can specify only one T-SQL query when calling the procedure. Of course, you can create a query that joins multiple tables, but this approach might not always work in your circumstances or might not be appropriate for the analytics you’re trying to perform. Fortunately, you can retrieve additional data directly within the R script.

In this article, we look at how to import data from a SQL Server table and from a .csv file. We also cover how to save data to a .csv file as well as insert that data into a SQL Server table. Being able to incorporate additional data sets or save data in different formats provides us with a great deal of flexibility when working with R Services and allows us to take even greater advantage of the many elements available to the R language for data analytics.

Another option is using the rodbc package to connect back to SQL Server to retrieve more data.

Related Posts

xgboost and Small Numbers of Subtrees

John Mount covers an interesting issue you can run into when using xgboost: While reading Dr. Nina Zumel’s excellent note on bias in common ensemble methods, I ran the examples to see the effects she described (and I think it is very important that she is establishing the issue, prior to discussing mitigation).In doing that I ran into one more […]

Read More

Reinforcement Learning with R

Holger von Jouanne-Diedrich takes us through concepts in reinforcement learning: At the core this can be stated as the problem a gambler has who wants to play a one-armed bandit: if there are several machines with different winning probabilities (a so-called multi-armed bandit problem) the question the gambler faces is: which machine to play? He could “exploit” one […]

Read More

Categories

November 2017
MTWTFSS
« Oct Dec »
 12345
6789101112
13141516171819
20212223242526
27282930