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«November 2015»

DirectQuery in Power BI Desktop

In the latest Power BI Desktop a new Preview features was released that now allows you to connect using DirectQuery to either SQL Server or Azure SQL Databases.  DirectQuery is a really neat feature that allows you to point to the live version of the data source rather than importing the data into a data model in Power BI Desktop. 

Normally when you want to get an updated dataset in the Power BI Desktop you would have to manually click the refresh button (this can be automated in the Power BI Service), which would initiate a full reimport of your data.  This refresh could take a variable amount of time depending on how much data your have.  For instance, if you’re refreshing a very large table you may be waiting quite a while to see the newly added data. 

With DirectQuery data imports are not required because you’re always looking at a live version of the data.  Let me show you how it works!

Turning on the DirectQuery Preview

Now, because DirectQuery is still in Preview you must first activate the feature by navigating to File->Options and settings->Options->Preview Features then check DirectQuery for SQL Server and Azure SQL Database


Once you click OK you may be prompted to restart the Power BI Desktop to utilize the feature.

Using DirectQuery in Power BI Desktop

Next make a connection either to an On-Premises SQL Server or Azure SQL database.

Go to the Home ribbon and select Get Data then SQL Server.


Provide your Server and Database names then click OK. ***Do not use a SQL statement.  It is not currently supported with DirectQuery***


From the Navigator pane choose the table(s) you would like to use.  I’m just going to pick the DimProduct table for this example and then click Load.  You could select Edit and that would launch the Query Editor where you could manipulate the extract.  This would allow you to add any business rules needed to the data before visualizing it.


Next you will be prompted to select what you want to connect to the data. Again, Import means the data

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The Big Data Blog Series

Over the last few years I’ve been speaking a lot on the subject of Big Data. I started by giving an intermediate session called “Show Me Whatcha’ Workin’ With”. This session was designed for people who had attended a one hour introductory session that showed you how to load data, to look at possible applications … Continue reading The Big Data Blog Series
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Does File Exist Check in SSIS

  • 7 November 2009
  • Author: DevinKnight
  • Number of views: 171316

A very common need in SSIS is to check to see if a file exist before you run what could be a very long process in your package.  There are no native tasks inside SSIS that can do this check but you can accomplish this using a Script Task.  Here are the steps to check to see if a file exist.


1.  Setup two variables.  The variable strFileLocation has a string data type with the value being the location of the file I want to check for.  The variable bolFileExists has a boolean data type with the value changing based on whether the file exist or not.  If the file is found the value will be changed to True otherwise it stays False.

2.  Use a Script Task in the Control Flow and set the ReadOnlyVariables to use the strFileLocation variable and the ReadWriteVariables to use the bolFileExists variable then select Edit Script.


3.  There are two methods for writing this script.  The first method you must first add the namespace System.IO.  The second method does not require this.


4.  Scroll down the editor until you find the green commented out text that says Add your code here.  Replace that with the following code then save and close the editor :

Dts.Variables("bolFileExists").Value = File.Exists(Dts.Variables("strFileLocation").Value)

The second option for the script is (Remember this option is not using the Imports System.IO step) :

Dts.Variables("bolFileExists").Value = My.Computer.FileSystem.FileExists(Dts.Variables("strFileLocation").Value)

5.  Now that you have the script done you can use things more familiar to you in SSIS like precedence constraints with expressions to get the desired results.  Connect the completed Script Task to a path that you want the package to move if the file does exist.  Open the precedence constraints editor by double clicking on the line. change the Evaluation operation to Expression and Constraint and add the expression @bolFileExists==True.  Remember the double equals is a comparison.  If it was a single equal sign it would be trying to set the value of the variable to True.  Click OK once complete.  If you want a path for if the file is not found then follow the same steps with the precedence constraint but the expression should be @bolFileExists==False.


I’m using script tasks just as placeholders here for how the rest of the package may look.  If my file did exist it would go down the left path.  If it did not exist my package flow would go right.

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