String functions (LEFT, RIGHT, CONTAINS) in Tableau - Dashboard Guide

Dashboard Mode - String functions (LEFT, RIGHT, CONTAINS)

Dashboard Goal

Understand how to use string functions LEFT, RIGHT, and CONTAINS in Tableau to analyze customer data by extracting parts of text and checking for keywords.

Sample Data

Customer ID	Full Name	Email	Region
101	Anna Smith	[e-mail]	North
102	Bob Johnson	[e-mail]	South
103	Clara Lee	[e-mail]	East
104	David Kim	[e-mail]	West
105	Eva Brown	[e-mail]	North

Dashboard Components

• KPI Card: First Name Extracted
  Formula: LEFT([Full Name], FIND([Full Name], ' ') - 1)
  Shows the first name part from the full name.
  Example: 'Anna Smith' -> 'Anna'
• KPI Card: Email Domain
  Formula: RIGHT([Email], LEN([Email]) - FIND([Email], '@'))
  Extracts the domain part of the email after '@'.
  Example: '[e-mail]' -> 'example.com'
• Bar Chart: Count of Customers with 'example.com' Email Domain
  Formula for filter: CONTAINS([Email], 'example.com')
  Shows how many customers have emails containing 'example.com'.
• Table: Customer Details with Extracted Names and Email Domains
  Columns: Customer ID, Full Name, First Name (LEFT), Email Domain (RIGHT), Region, Email Contains 'example.com' (CONTAINS)
  Helps see all string function results side by side.

Dashboard Layout

+----------------------+----------------------+----------------------+
|  First Name Extracted |   Email Domain       |  Email Domain Count  |
|      (KPI Card)       |     (KPI Card)       |    (Bar Chart)       |
+----------------------+----------------------+----------------------+
|                      Customer Details Table                      |
|                      (with all string function columns)         |
+-----------------------------------------------------------------+

Interactivity

Applying a filter on Region updates all components to show data only for that region. For example, selecting 'North' filters the table, KPI cards, and bar chart to customers from North region.

Clicking on the bar chart segment for 'example.com' emails filters the table and KPI cards to only customers whose emails contain 'example.com'.

Self Check

If you add a filter for Region = East, which components update and what data do they show?

• The KPI cards update to show first names and email domains only for customers in East region.
• The bar chart updates to count only customers in East region with emails containing 'example.com'.
• The table updates to show only customers from East region with all string function columns.

Key Result

Dashboard demonstrating LEFT, RIGHT, and CONTAINS string functions in Tableau to extract and analyze customer name and email data.

Practice

1. What does the Tableau function LEFT('Tableau', 3) return?

easy

A. 'Tab'

B. 'bleau'

C. 'Table'

D. 'au'

Solution

1. Step 1: Understand LEFT function

   The LEFT function extracts characters from the start of a string. Here, it extracts 3 characters from 'Tableau'.

2. Step 2: Extract first 3 characters

   The first 3 characters of 'Tableau' are 'Tab'.

3. Final Answer:

   'Tab' -> Option A

4. Quick Check:

   LEFT('Tableau', 3) = 'Tab' [OK]

Hint: LEFT gets characters from the start of text [OK]

Common Mistakes:

• Confusing LEFT with RIGHT function
• Extracting more or fewer characters than specified
• Assuming it extracts from the end

2. Which of the following is the correct syntax to check if the string 'Data' contains the letter 'a' in Tableau?

easy

A. LEFT('Data', 'a')

B. CONTAINS('Data', 'a')

C. CONTAINS('a', 'Data')

D. RIGHT('Data', 'a')

Solution

1. Step 1: Understand CONTAINS syntax

   CONTAINS(text, substring) checks if substring exists in text. The first argument is the main text, second is what to find.

2. Step 2: Apply to given strings

   To check if 'Data' contains 'a', use CONTAINS('Data', 'a').

3. Final Answer:

   CONTAINS('Data', 'a') -> Option B

4. Quick Check:

   CONTAINS('Data', 'a') = TRUE [OK]

Hint: CONTAINS(text, substring) order matters: text first [OK]

Common Mistakes:

• Swapping the order of arguments in CONTAINS
• Using LEFT or RIGHT instead of CONTAINS
• Passing characters as numbers

3. What is the result of RIGHT('Analytics', 4) in Tableau?

medium

A. 'tics'

B. 'Anal'

C. 'ytic'

D. 'naly'

Solution

1. Step 1: Understand RIGHT function

   RIGHT extracts characters from the end of a string. Here, it extracts 4 characters from 'Analytics'.

2. Step 2: Extract last 4 characters

   The last 4 characters of 'Analytics' are 'tics'.

3. Final Answer:

   'tics' -> Option A

4. Quick Check:

   RIGHT('Analytics', 4) = 'tics' [OK]

Hint: RIGHT gets characters from the end of text [OK]

Common Mistakes:

• Extracting characters from the start instead of end
• Counting wrong number of characters
• Confusing with LEFT function

4. You wrote the formula CONTAINS('Business', Business) in Tableau but it gives an error. What is the problem?

medium

A. The first argument should be a number

B. CONTAINS cannot be used with text

C. LEFT function should be used instead

D. Missing quotes around 'Business' in second argument

Solution

1. Step 1: Check CONTAINS argument types

   CONTAINS requires both arguments to be text strings or fields. Here, second argument is missing quotes, so Tableau treats it as a field name.

2. Step 2: Fix by adding quotes

   Adding quotes around 'Business' in second argument makes it a string literal, fixing the error.

3. Final Answer:

   Missing quotes around 'Business' in second argument -> Option D

4. Quick Check:

   CONTAINS('Business', 'Business') works [OK]

Hint: Always quote text strings inside CONTAINS [OK]

Common Mistakes:

• Using unquoted text instead of string literals
• Confusing CONTAINS with LEFT or RIGHT
• Passing numbers instead of text

5. You want to create a calculated field in Tableau that returns TRUE if the first 2 letters of a product code are 'AB' and the code contains '123'. Which formula is correct?

hard

A. CONTAINS([Product Code], 'AB') AND LEFT([Product Code], 3) = '123'

B. RIGHT([Product Code], 2) = 'AB' OR CONTAINS('123', [Product Code])

C. LEFT([Product Code], 2) = 'AB' AND CONTAINS([Product Code], '123')

D. LEFT([Product Code], 2) = 'AB' AND CONTAINS('123', [Product Code])

Solution

1. Step 1: Check LEFT function usage

   LEFT([Product Code], 2) extracts first 2 letters. We compare it to 'AB' to check the start.

2. Step 2: Check CONTAINS usage

   CONTAINS([Product Code], '123') checks if '123' is anywhere in the code. The order is correct: main text first, substring second.

3. Step 3: Combine conditions with AND

   Both conditions must be true, so use AND.

4. Final Answer:

   LEFT([Product Code], 2) = 'AB' AND CONTAINS([Product Code], '123') -> Option C

5. Quick Check:

   Correct syntax and logic = LEFT([Product Code], 2) = 'AB' AND CONTAINS([Product Code], '123') [OK]

Hint: Use LEFT for start, CONTAINS for anywhere, combine with AND [OK]

Common Mistakes:

• Swapping LEFT and RIGHT functions
• Reversing arguments in CONTAINS
• Using OR instead of AND