Guide to DAX Ch 2: Introducing DAX

Question 1

The table name needs to be included when referencing a measure or a calculated column?

Answer 1

Calculated column

Question 2

What is the answer and data type of the following expression:

“5”+”4”

Answer 2

9, integer

Question 3

T/F: A variant data type can be used as a data type for a column in a regular table.

Answer 3

False

Question 4

When should you use calculated columns (3 items)?

Answer 4

1. To place items in a slicer
2. Define expression that is strictly bound to the current row.
3. Categorize text or numbers.

Question 5

When should you use a measure?

Answer 5

1. To display calculation values that reflect user selections, and the values need to be presented as aggregates in a report.

Question 6

What are 3 types of errors that may appear in DAX?

Answer 6

1. Conversion
2. Arithmetic
3. Empty/missing values

Question 7

Describe a conversion error.

Answer 7

It’s when 2 incompatible data types are in an expression such that nothing can be evaluated. For example, you can’t add a string to an integer.

Question 8

Describe an arithmetic error.

Answer 8

Mathematical operation error like taking the sqrt of a negative value.

Question 9

Give some examples of aggregation functions.

Answer 9

Sum, Average, min, max

Question 10

Give some examples of logical functions.

Answer 10

Switch, If, IfError, And, Not, Or, True, False

Question 11

Give some examples of information functions.

Answer 11

ISBlank, IsError, IsLogical, IsNonText, IsNumber, IsText

Question 12

Give some examples of mathematical functions.

Answer 12

Abs, Exp, Fact, LN, Log, Log10, PI, Power, Sign, SQRT, GCD, LCM

Question 13

Give some examples of Trigonometric functions.

Answer 13

COS, COSH, COT COTH, SIN, SINH, TAN, TANH

Question 14

Give some examples of text functions.

Answer 14

Concatenate, exact, find, fixed, format, left, len, lower, mid, replace, rept, right, search, substitute, trim, upper, value

Question 15

Give some examples of conversion functions.

Answer 15

INT, Currency, Date, Time, DateTime

Question 16

Give some examples of Date and Time functions.

Answer 16

DateValue, Date, Time, Now, DateTime, Hour, Minute,Today, Weekday, Year, WeekNum, YearFrac

Question 17

Give some examples of relational functions.

Answer 17

Related, RelatedTable

Question 18

When do you use the Related function, and when do you used RelatedTable?

Answer 18

1. Related - when you are on the many side needing a column from the 1 side of a relationship.
2. Relatedtable - when you are on the 1 side needing columns from the many side of a relationship.

Question 19

When are calculated columns computed? Do the values change depending on user selection?

Answer 19

At data refresh time. No.

Question 20

When are measures computed? Do the values change depending on user selection?

Answer 20

At query time. Yes.