Splitting and merging columns in Power BI - Dashboard Guide

Dashboard Mode - Splitting and merging columns

Business Question

How can we split full customer names into first and last names, and merge city and state into a single location column for better analysis?

Sample Data

CustomerID	FullName	City	State	Sales
101	John Smith	Seattle	WA	250
102	Mary Johnson	Portland	OR	300
103	James Lee	San Francisco	CA	400
104	Linda Davis	Denver	CO	150
105	Michael Brown	Seattle	WA	350

Dashboard Components

• KPI Card: Total Sales with formula =SUM(Sales) showing 1450
• Table: Customer details with split columns FirstName and LastName created by splitting FullName at the space.
• Table: Location column created by merging City and State with a comma and space.
• Bar Chart: Sales by Location showing total sales per city-state combination.

Formulas / Expressions

// Split FullName into FirstName
FirstName = LEFT(Customer[FullName], FIND(" ", Customer[FullName]) - 1)

// Split FullName into LastName
LastName = RIGHT(Customer[FullName], LEN(Customer[FullName]) - FIND(" ", Customer[FullName]))

// Merge City and State into Location
Location = Customer[City] & ", " & Customer[State]

// Total Sales measure
Total Sales = SUM(Customer[Sales])
  

Dashboard Layout

+----------------------+-------------------------+
|      Total Sales      |      Sales by Location   |
|       (KPI Card)      |       (Bar Chart)        |
+----------------------+-------------------------+
|        Customer Details Table (with split names and merged location)       |
+-----------------------------------------------------------------------------+
  

Interactivity

A slicer on Location allows filtering the bar chart and the customer details table to show only customers from the selected city-state. Selecting a location updates the total sales KPI to reflect sales only from that location.

Self Check

If you add a filter for Location = "Seattle, WA", which components update and what will the total sales show?

• The bar chart will show sales only for Seattle, WA.
• The customer details table will list only customers from Seattle, WA.
• The total sales KPI will update to show 600 (250 + 350).

Key Result

Dashboard showing customer sales with split first and last names and merged city-state location for filtering and analysis.

Practice

1. What does splitting a column in Power BI do?
Splitting means:

easy

A. Breaking one column into multiple columns based on a rule

B. Joining multiple columns into one column

C. Deleting unwanted columns from the table

D. Changing the data type of a column

Solution

1. Step 1: Understand the meaning of splitting

   Splitting means dividing one column into several columns based on a delimiter or rule.

2. Step 2: Compare with other options

   Joining columns is merging, deleting is removing, and changing data type is different from splitting.

3. Final Answer:

   Breaking one column into multiple columns based on a rule -> Option A

4. Quick Check:

   Splitting = Breaking column into parts [OK]

Hint: Splitting breaks one column into parts [OK]

Common Mistakes:

• Confusing splitting with merging
• Thinking splitting deletes columns
• Mixing splitting with data type changes

2. Which of the following is the correct way to merge two columns FirstName and LastName with a space separator in Power Query?

easy

A. Table.RemoveColumns(Source, {"FirstName", "LastName"})

B. Table.SplitColumn(Source, "FullName", Splitter.SplitTextByDelimiter(" "))

C. Table.AddColumn(Source, "FullName", each [FirstName] & " " & [LastName])

D. Table.TransformColumnTypes(Source, {"FullName", type text})

Solution

1. Step 1: Identify merging syntax in Power Query

   Merging columns uses Table.AddColumn with an expression combining columns using & and a separator.

2. Step 2: Check each option

   Table.AddColumn(Source, "FullName", each [FirstName] & " " & [LastName]) correctly concatenates FirstName and LastName with a space. Table.RemoveColumns removes columns, Table.SplitColumn splits columns, Table.TransformColumnTypes changes data types.

3. Final Answer:

   Table.AddColumn(Source, "FullName", each [FirstName] & " " & [LastName]) -> Option C

4. Quick Check:

   Merge = AddColumn with & [OK]

Hint: Use & with space inside AddColumn to merge columns [OK]

Common Mistakes:

• Using SplitColumn instead of AddColumn for merging
• Forgetting the space separator
• Removing columns instead of merging

3. Given a column FullName with values like "John Doe", what will be the result of this Power Query step?

Table.SplitColumn(Source, "FullName", Splitter.SplitTextByDelimiter(" "), {"FirstName", "LastName"})

medium

A. Two new columns named FirstName and LastName with split parts

B. A single column with names joined by space

C. An error because SplitColumn needs a number of columns

D. The FullName column deleted from the table

Solution

1. Step 1: Understand SplitColumn with delimiter

   This function splits the FullName column by space into two columns named FirstName and LastName.

2. Step 2: Check other options

   A single column with names joined by space is merging, not splitting. An error because SplitColumn needs a number of columns is incorrect because specifying new column names is valid. The FullName column deleted from the table is false; the original column is replaced by new columns.

3. Final Answer:

   Two new columns named FirstName and LastName with split parts -> Option A

4. Quick Check:

   SplitColumn with delimiter creates multiple columns [OK]

Hint: SplitColumn with delimiter creates named new columns [OK]

Common Mistakes:

• Thinking SplitColumn merges columns
• Assuming original column remains unchanged
• Believing it causes an error without column count

4. You tried to merge columns City and Country using this code:

Table.AddColumn(Source, "Location", each [City] + ", " + [Country])

But you get an error. What is the likely cause?

medium

A. Missing a space after the comma separator

B. Using + operator instead of & for text concatenation

C. Table.AddColumn cannot merge columns

D. Column names are case sensitive and incorrect

Solution

1. Step 1: Check concatenation operator in Power Query

   Power Query uses & to join text, not + which causes an error.

2. Step 2: Review other options

   Missing space after comma is not an error, AddColumn can merge columns, and case sensitivity depends on source but usually not error here.

3. Final Answer:

   Using + operator instead of & for text concatenation -> Option B

4. Quick Check:

   Use & for text join, not + [OK]

Hint: Use & to join text columns, not + [OK]

Common Mistakes:

• Using + instead of & for text
• Assuming AddColumn can't merge
• Ignoring case sensitivity issues

5. You have a column Address with values like "123 Main St, Springfield, IL". You want to split it into Street, City, and State columns. Which Power Query step correctly splits this?

hard

A. Table.TransformColumns(Source, {"Address", each Text.Split(_, ", ")})

B. Table.AddColumn(Source, "Street", each Text.BeforeDelimiter([Address], ", "))

C. Table.SplitColumn(Source, "Address", Splitter.SplitTextByEachDelimiter({","}), {"Street", "City", "State"})

D. Table.SplitColumn(Source, "Address", Splitter.SplitTextByDelimiter(", "), {"Street", "City", "State"})

Solution

1. Step 1: Identify correct delimiter and split method

   The address uses ", " as delimiter, so SplitTextByDelimiter with ", " is correct to split into three columns.

2. Step 2: Evaluate other options

   Table.AddColumn(Source, "Street", each Text.BeforeDelimiter([Address], ", ")) only extracts Street, not full split. Table.SplitColumn(Source, "Address", Splitter.SplitTextByEachDelimiter({","}), {"Street", "City", "State"}) uses SplitTextByEachDelimiter with wrong delimiter format. Table.TransformColumns(Source, {"Address", each Text.Split(_, ", ")}) splits but does not create separate columns.

3. Final Answer:

   Table.SplitColumn(Source, "Address", Splitter.SplitTextByDelimiter(", "), {"Street", "City", "State"}) -> Option D

4. Quick Check:

   SplitColumn with correct delimiter and column names [OK]

Hint: Use SplitTextByDelimiter with exact separator and column names [OK]

Common Mistakes:

• Using wrong delimiter like comma without space
• Extracting only one part instead of splitting all
• Not naming new columns after split