Top DAX Interview Questions (2024)
What is DAX?
What is a DAX Function?
How are DAX functions different from Excel functions?
What are the most common DAX functions used?
Which of the DAX functions do not return a table?
Are DAX functions case sensitive?
What are DAX Aggregation functions?
Q: What is DAX?
Ans:
Data Analysis Expressions (DAX) is a formula expression language in Excel that is utilised in Analysis Services, Power BI, and Power Pivot. Functions, operators, and values are used in DAX formulas to execute complex computations and queries on data in associated tables and columns in tabular data models.
Q: What is a DAX Function?
Ans:
A DAX function is a built-in function in the DAX language that allows you to execute several operations on the data in your Data Model's tables.
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Q: How are DAX functions different from Excel functions?
Ans:
Excel functions |
DAX functions |
|
Excel functions use a cell reference or a range of cells. |
DAX functions use columns or tables for cell reference. |
|
Excel's date and time functions return an integer that denotes a date. |
DAX returns a datetime data type. |
|
There are no functions in Excel that return a table, however it works with arrays. |
DAX has many functions that simply refer to tables and columns in order to do computations and return a table or column of values. |
Q: What are the most common DAX functions used?
Ans:
Below are some essential DAX Functions in Power BI:
- FILTER function returns a subset of an expression or a table.
FILTER(<table>,<filter>) - We could use ALL function to retrieve all of the values in a column or all of the
rows in a given table, overriding any earlier filters.
ALL(<table> or <column>) - RELATED Function : This DAX function is intended to let you return a relevant value from a
table other than the one you're currently working on.
RELATED(<column>) - TOTALYTD / TOTALQTD / TOTALMTD : This function is identical to the date and time functions
in Microsoft Excel.
TOTALYTD(<expression>,<dates>[,<filter>][,<year_end_date>]) - CALCULATE: With minimal effort, this function can ease complex and multiple calculations.
The DAX CALCULATE function evaluates an expression in a context that has been altered by
filters.
CALCULATE(<expression>, <filter1>,<filter2>â¦)
Q: Which of the DAX functions do not return a table?
Ans:
Date and time functions in DAX return a datetime data type that is available in DAX.
Q: Are DAX functions case sensitive?
Ans:
As a formula language, DAX is case-insensitive. If we utilize SQL Server Analysis Services, we can select between case-sensitive and case-insensitive collation styles.
Q: What are DAX Aggregation functions?
Ans:
DAX Aggregation functions are important in calculations since they aggregate any expression across the rows of a table. DAX Aggregations functions are ADDCOLUMNS, AVERAGE, AVERAGEA, AVERAGEX, COUNT, COUNTA, COUNTAX, COUNTBLANK, COUNTROWS, COUNTX, CROSSJOIN, DISTINCTCOUNT, GENERATE, GENERATEALL, MAX, MAXA, MAXX, MIN, MINA, MINX, PRODUCT, PRODUCTX, ROW, SELECTCOLUMNS, SUM, SUMMARIZE, SUMMARIZE with Options SUMX, TOPN.