Type conversion functions in Tableau - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the INT() function do in Tableau?

The INT() function converts a value to an integer by removing any decimal part. For example, INT(3.7) returns 3.

beginner

How do you convert a string to a date in Tableau?

Use the DATE() function to convert a string that represents a date into a date data type. For example, DATE('2024-06-01') returns a date value.

beginner

What is the purpose of the STR() function in Tableau?

STR() converts a number or date into a string. For example, STR(2024) returns "2024" as text.

intermediate

Explain the FLOAT() function in Tableau.

FLOAT() converts a value to a floating-point number (decimal). For example, FLOAT('3.14') returns 3.14 as a number.

intermediate

What happens if you try to convert a non-date string with DATE() in Tableau?

Tableau returns a NULL value if the string cannot be converted to a valid date.

Which Tableau function converts a number to a string?

A STR()

B INT()

C DATE()

D FLOAT()

STR() converts numbers or dates into text strings.

What does INT(5.99) return in Tableau?

A 5

B 6

C 5.99

D NULL

INT() removes the decimal part, so INT(5.99) returns 5.

Which function converts a string like '2024-06-01' to a date?

A FLOAT()

B INT()

C DATE()

D STR()

DATE() converts a string to a date data type.

What will FLOAT('3.14') return?

A NULL

B 3

C '3.14'

D 3.14

FLOAT() converts the string to a decimal number 3.14.

If DATE('hello') is used, what does Tableau return?

A Current date

B NULL

C 'hello'

D Error message

Invalid date strings return NULL in Tableau.

Describe how to convert a number to a string and a string to a date in Tableau.

Think about functions that change data types from number to text and text to date.

What happens when you use INT() on a decimal number and when DATE() receives an invalid string?

Consider how Tableau handles type conversion errors or rounding.

Practice

1. Which Tableau function converts a string like '123' into an integer?

easy

A. FLOAT()

B. STR()

C. DATE()

D. INT()

Solution

1. Step 1: Understand the input type

   The input is a string '123' which represents a number but is stored as text.

2. Step 2: Choose the function to convert string to integer

   INT() converts a string that looks like a number into an integer type.

3. Final Answer:

   INT() -> Option D

4. Quick Check:

   String '123' to number = INT() [OK]

Hint: Use INT() to convert numeric strings to whole numbers [OK]

Common Mistakes:

• Using STR() which converts numbers to strings
• Using DATE() which converts to date format
• Using FLOAT() when integer is needed

2. Which of the following is the correct syntax to convert a date string '2023-06-01' to a date in Tableau?

easy

A. FLOAT('2023-06-01')

B. DATE('2023-06-01')

C. INT('2023-06-01')

D. STR('2023-06-01')

Solution

1. Step 1: Identify the data type to convert to

   The string '2023-06-01' represents a date, so we want to convert it to a date type.

2. Step 2: Use the DATE() function for conversion

   DATE() converts a string formatted as a date into a Tableau date type.

3. Final Answer:

   DATE('2023-06-01') -> Option B

4. Quick Check:

   Convert date string to date = DATE() [OK]

Hint: Use DATE() to convert date strings to date type [OK]

Common Mistakes:

• Using STR() which converts to string, not date
• Using INT() or FLOAT() which cause errors on date strings
• Missing parentheses in function call

3. What is the result of this Tableau calculation?

INT('45.67')

medium

A. Error

B. 45

C. 46

D. 45.67

Solution

1. Step 1: Analyze the input string

   The string '45.67' represents a decimal number.

2. Step 2: Understand INT() behavior on decimal strings

   INT() expects a string representing an integer; passing a decimal string causes an error in Tableau.

3. Final Answer:

   Error -> Option A

4. Quick Check:

   INT('45.67') causes error [OK]

Hint: INT() only converts strings representing whole numbers [OK]

Common Mistakes:

• Expecting an error on decimal strings
• Thinking INT() rounds up to 46
• Confusing truncation with keeping decimals

4. You wrote this Tableau formula but get an error:

FLOAT('abc')

What is the likely cause?

medium

A. The string 'abc' cannot convert to a number

B. FLOAT() requires a date input

C. Missing quotation marks around abc

D. FLOAT() only works on integers

Solution

1. Step 1: Check the input string

   The string 'abc' contains letters, not numeric characters.

2. Step 2: Understand FLOAT() conversion rules

   FLOAT() converts strings representing numbers to decimal numbers; non-numeric strings cause errors.

3. Final Answer:

   The string 'abc' cannot convert to a number -> Option A

4. Quick Check:

   Non-numeric string to FLOAT() = Error [OK]

Hint: Only numeric strings convert with FLOAT() [OK]

Common Mistakes:

• Thinking FLOAT() works on any string
• Assuming FLOAT() needs date input
• Forgetting quotes around strings

5. You have a field [Sales] stored as string values like '1000', '2000', and '3000'. You want to calculate the average sales as a number. Which formula correctly converts and averages these values?

hard

A. INT(AVG([Sales]))

B. AVG(STR([Sales]))

C. AVG(INT([Sales]))

D. AVG(DATE([Sales]))

Solution

1. Step 1: Convert string sales to numbers before averaging

   Since [Sales] is string, convert each value to integer using INT() first.

2. Step 2: Apply AVG() on converted integers

   AVG(INT([Sales])) calculates the average of numeric sales correctly.

3. Final Answer:

   AVG(INT([Sales])) -> Option C

4. Quick Check:

   Convert then average = AVG(INT()) [OK]

Hint: Convert strings to numbers before aggregation [OK]

Common Mistakes:

• Averaging strings directly causes errors
• Converting after averaging strings is invalid
• Using DATE() on numeric strings