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In this blog post, intended for new Power BI developers, I identify some easy-to-use features that I wish I had started using at the beginning of my Power BI journey. My goal is to familiarize you with a few key concepts that will help you get more value out of Power BI. Learning and harnessing these features will help you take your report development skills to the next level.
Before loading data into Power BI, you will want to review the structure of the data and make changes to it as needed. Where does all of that transformation magic happen? The Power Query Editor! Power Query is Microsoft’s data transformation and preparation engine and the Power Query Editor is the graphical user interface for modifying and shaping your data before loading it into Power BI.
You can access the Power Query Editor in one of two ways. The first way is through the ‘Get Data’ process. Once you select your data source, click on ‘Transform Data’ to get to the Power Query Editor. The second way to get there is by clicking on the ‘Transform Data’ button on the home ribbon.
Let’s take a tour of the Query Editor:
Here are some common transformations you can make from the Query Editor:
Taking some time to learn how to transform your data in the Query Editor will enable you to properly shape your data so that it’s ready to be visualized.
Within the Power Query Editor, you will find three valuable tools for exploring data quality and identifying issues. Those three tools are column quality, column distribution, and column profile. From the View tab in the Query Editor, check the box to enable each one.
Column Quality: Shows the percentage of rows within a column that are valid, empty, or errors. From there you can hover over the summary box (or right-click on the column quality section) for additional prompts to correct any issues.
Column Distribution: Shows the number of distinct and unique values within a column. Bonus tip: if a column has the same number of distinct and unique values, that field can serve as the primary key for that table. For example, in the table below, we know that Row ID is the primary key for this table because it is the unique identifier for each row of data in the table.
Column Profile: Colum profile provides additional summary statistics and a bar chart showing the distribution of values in the column. For example, you would use this to check which values for a dimension are present or to evaluate the minimum and maximum values for numeric data.
Bonus Tip: Column profiling is based on the first 1000 rows by default. If your dataset is larger than that, make sure to change it to profile based on the entire dataset (this is located at the bottom of the Power Query Editor).
What is a Data Model? A data model defines the relationship between tables. Because you are often bringing in data from multiple sources, you need to create a good data model to define the links between the data sources. In Power BI Desktop, you can access the data model via the Model view on the left-hand side navigation.
Here are some best practices for data modeling:
How to set up a good data model. Let’s take a look at an example of a data model from a global kitchen supply retailer.
Here, we have one fact table (Sales), that “looks up” to several dimension tables (Products, Customer Type, Regions, and Calendar). The Sales table is connected to each lookup table with a linked field using a many-to-one relationship. For example, there are many instances of Product Key in the Sales tables that relate to one instance of Product Key in the Products table.
Connecting tables is as easy as dragging a field from one table onto the related field in the other. After forming relationships, you can hover over the connecting line and double-click on it to view and change the properties. Note that Power BI will try to detect the relationships, but you can turn this feature off to have more control over creating your own data model.
Navigation: File > Options and settings > Options > CURRENT FILE > Data Load
Creating a good data model helps with making your data ready for visualization and enhances the efficiency of your report.
If you don't know much DAX (DAX stands for Data Analysis Expression and is the formula language of Power BI), take advantage of Quick Measures! Quick Measures allow you to drag and drop fields to create measures such as:
You can access Quick Measures either from the top ribbon or by clicking on the three ellipses next to a table in the Fields pane. You then use the Quick Measures interface to drag and drop fields into the right spots. When you create a Quick Measure, Power BI writes the DAX syntax behind the scenes. This is a great way to start using measures as you’re ramping up with learning DAX.
One way to make your visualizations and reports stand out is to ditch the default formatting and jazz it up with some design updates! There is nothing wrong with using the default formatting, but Power BI has some built-in formatting options to help you take your reports to the next level. Here are my top formatting tips:
1. Use the theme editor in the View tab to update the entire report theme.
2. Change the report page background color or add a background image. Click on the blank space in the report canvas and use the paintbrush to access the page formatting.
3. For visual-level formatting, turn off gridlines on the X and Y axis formatting. For all visual-level formatting, click on a visual and access all of the formatting options in the Visualizations pane.
4. Use custom colors. Update chart colors under the Data colors and Background sections of the visualization formatting. Give your chart a different background than the report page to add some contrast. For determining what colors to use, refer to your company’s brand guide if they have one. I also like to use Adobe Color Wheel as a color scheme resource. I’m also a big fan of the Site Palette Chrome extension which you can use to extract colors from any website.
5. Turn on the visualization Border and set the radius to 10 for rounded edges.
6. Turn on the visualization Shadow to create a ‘drop-shadow’ effect.
7. Use the Format Painter to quickly apply formatting from one visual to another.
Here’s a look at a report after applying a few of these formatting techniques.
BEFORE:
AFTER:
In summary, we have covered topics including the Power Query Editor, data profiling, data modeling, Quick Measures, and formatting. These five areas are important areas you can focus on to improve your Power BI skills. Hopefully, you have learned something new about Power BI that will take your skills to the next level!
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