What are the different data types used in Dax ? Power BI interview questions and answers 219

 What are the different data types used in Dax ?

DAX (Data Analysis Expressions) employs a variety of data types to ensure accurate calculations and data manipulation within Power BI. Here's a breakdown of the key types:

1. Text Data Types:

• Text: Represents plain text, such as names, descriptions, or addresses.

• Formatted Value: Stores text with specific formatting, commonly used for currency, dates, or percentages.

2. Numeric Data Types:

• Whole Number: Stores integer values without decimals (e.g., 1, 5, 100).

• Decimal Number: Stores numerical values with decimal places (e.g., 3.14, 125.50).

• Currency: Represents monetary values with specific currency formatting.

• Fixed Decimal Number: Stores decimal numbers with a fixed number of decimal places, ensuring consistent precision in calculations.

3. Date and Time Data Types:

• Date: Stores calendar dates (e.g., 2023-12-30).

• Time: Stores time values (e.g., 10:30:00 AM).

• Date/Time: Combines date and time information (e.g., 2023-12-30 10:30:00 AM).

• Duration: Represents time intervals (e.g., 2 days, 4 hours).

4. Logical Data Types:

• True/False: Stores Boolean values, indicating true or false conditions.

5. Other Data Types:

• Blank: Represents empty or missing values.

• Error: Indicates an error in a calculation or data value.

• Table: Represents a table of data within a DAX formula, enabling complex calculations across multiple columns and rows.

Understanding these data types is crucial for:

• Creating accurate DAX measures and calculated columns.

• Ensuring correct data representation in visuals and calculations.

• Writing efficient DAX formulas that handle different data types appropriately.

• Performing data transformations and cleaning tasks effectively.

Additional Tips:

• Use the Data Type drop-down in the Power BI data model to view and change the data type of columns.

• Employ DAX functions like CONVERT and VALUE to convert between data types within formulas.

• Be mindful of data type compatibility when performing calculations and comparisons.

By mastering DAX data types, you'll enhance your ability to create robust calculations, accurate visualizations, and meaningful insights within your Power BI reports and models.