Microsoft Data Analyst Associate DA-100 Training | Day 2 Q/A Review

This blog post covers a brief overview of the topics covered and some common questions asked on Day 2 Live Interactive training on Microsoft Data Analyst Associate [DA-100]

This post will help you learn about Clean, Transform, and loading the data in Power BI and prepare you for the certification and get a better-paid job in the field of Data Analyst.

On our Day 2 Live Session, we have covered how to Simplify the Data Structure, Profile the Data, Power Query, Combining Multiple tables into single, and performed hand-on Lab 2 out of 11 hands-on Labs. We learned about how to apply various transformations and apply queries to load them to the data model and many more.

>Power Query Editor

• Power Query Editor in Power BI Desktop allows you to shape (transform) your imported data.
• Actions such as renaming columns or tables, changing text to numbers, removing rows, setting the first row as headers, and much more can be accomplished.
  

Source: Microsoft

>Shape the Initial Data

• After importing data from various sources. We need to shape the data
• To shape the data we can use Power Query Editor
• Power query editor helps us to shape the data like we can rename the columns or rows, changing texts to numbers, etc.
• When our data is flat, and we wanted to convert our data into a table, we can use the Pivot columns feature.
• Pivot columns enable us to convert flat data into a table that contains an aggregate value for each unique value in the column.
  

Source: Microsoft

>Simplify the Data Structure

• When you import data from multiple sources into Power BI Desktop, the data retains its predefined table and column names.
• You might want to change some of the names so that they are in a consistent format, easier to work with, and more meaningful to a user.
• You can use Power Query Editor in Power BI Desktop to make these name changes and simplify your data structure.

>Minimizing Errors using Power Query Editor

• When you import a table from any data source, Power BI Desktop automatically starts scanning the first 1,000 rows (default setting) and tries to detect the type of data in the columns.
• Some situations might occur where Power BI Desktop does not detect the correct data type. Where incorrect data types occur, you will experience performance issues.
•  You may get a higher chance of getting data type errors while dealing with flat files, such as comma-separated values (.CSV) files and Excel workbooks (.XLSX), because of entering the data manually into the worksheets and mistakes were made.
• So the best practice is to evaluate the column data types in Power Query Editor before you load the data into a Power BI data model

>Profile Data in Power BI

• Profiling data means studying every detail of the data
• It can be identifying anomalies, detecting errors.
• After examining the data, it moves forward for query statistics like row counts, maximum and minimum value, etc.
• This is the most important concept in the whole data analyst process as it allows us to shape and organize the data
• If the data is well organized we can interact with it easily
• We can make reports with fewer efforts

Source: Microsoft

>Combining Multiple Rows into Single Table

We can combine multiple columns into a single table when :

• When too many tables exist, it will be difficult to navigate an overly complicated data model.
• Several tables have a similar role.
• In a table, only a column or two can fit into a different table
• You want to use several columns from different tables in a custom column.

We can join two tables together in the following ways:

1. Left Outer: It Displays all the rows from the first table and only the matching rows from the second table
2. Full Outer: Displays all the rows from both first and second tables
3. Inner: Displays only the matched rows between the two tables

FAQ Asked during the Session:

Q1:What is a Power Query?

A. Power Query is a data transformation and data preparation engine. Power Query comes with a graphical interface for getting data from sources and a Power Query Editor for applying transformations.

Source: Microsoft

Q2: Is query folding available only if you are pulling data from a single table?

A. Yes, Query folding is the ability for a Power Query to generate a single query statement to retrieve and transform source data.

Q3: How can we join two or more tables in Power BI?

A. In Power BI Desktop, you can join two tables with Merge menu item in the Query Editor, in-home tab, Under Combine, Merge Queries

To know more, click here

Q4: What is the difference between Power BI Desktop and Power BI Service?

A.Power BI Desktop is a Windows application running on the local computer. It is a client machine that can connect with a variety of data sources from your computer to the data in the local computer or the data in the server.

Power BI Service is a cloud-based service where users interact with the reports and view. The desktop application is used by Report Designers to publish the Power BI reports to the Service.

Source: Microsoft

Q5: What are some of the differences in data modeling between Power BI Desktop and Power Pivot for Excel?

A. Power Pivot for Excel supports only single directional relationships (one to many), calculated columns, and one import mode.
Power BI Desktop supports bi-directional cross-filtering relationships, security, calculated tables, and multiple import options.

Q6: What is grouping in Power BI Desktop?

A.Power BI Desktop allows you to group the data into small chunks. you should use Ctrl + click for grouping to select multiple elements in the visual. Right-click on one of those elements which appear in the group’s window.

Q7: Is Power BI better than Excel?

A. Power BI is a more powerful tool compared to Microsoft Excel. Power BI is easy to use and is much more flexible, while Microsoft Excel is not so handy to use. Power BI has mostly been used for data dashboards and visualization sharing to a large number of users, while Microsoft Excel is mostly used for in-depth driver analysis.

Q8: Name the language that is used in the power query?

A.M-language is a programming language is used in Power Query. This language is quite similar to other languages and easy to use. Also, it is case-sensitive

Q9: What is the Power BI Designer?

A. Power BI Designer is a stand-alone application to make Power BI reports; it does not require excel. It is the combination of Power Pivot, Power View, and Power Query.

Q10:What are Data Anomalies?

A. Data anomalies are outliers within our data.

Q10: What is self-service business intelligence?

A. SSBI is an approach to data analytics that enables business users to filter, analyze, and segment their data without the in-depth technical knowledge in statistical analysis, business intelligence (BI).

Q11:What are the data destinations for Power Queries?

A. There are two destinations for output we get from power query:

• Load to a table in a worksheet
• Load to the Excel Data Model

Quiz Time (Sample Exam Questions)

With our Microsoft Data Analyst Associate, we cover Over 100+ Sample questions to help you prepare for the Certification [DA-100]

Check out these Questions:

Ques: You need to import huge datasets in the Power Query Editor. You want to check whether a column consists of only the unique values. Which of the below given Data Preview Options can be used for the given purpose? (Select Multiple Options)

A. Column Profile

B. Show White spaces

C. Column Distribution

D. Monospaced

E. Column Quality

Comment your answer in the comment box.

References

• Microsoft Certified Data Analyst Associate [DA-100]: Everything You Need To Know
• Microsoft Certified Data Analyst Associate [DA-100]  Step By Step Activity Guides (Hands-On Labs)
• What is Power Query | Microsoft Azure Power BI Tool
• How to Transform Data in Power BI – Clean and Load Data in Power Query

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