Why Splitting and merging columns in Power BI? - Purpose & Use Cases

The Big Idea

What if you could fix messy data in seconds instead of hours?

The Scenario

Imagine you have a big spreadsheet where names and emails are all mixed in one column, or addresses are split across several columns. You need to separate or combine these to make sense of the data.

The Problem

Doing this by hand means copying, pasting, and typing over and over. It's slow, easy to make mistakes, and if the data changes, you have to start all over again.

The Solution

Splitting and merging columns in Power BI lets you quickly break apart or join data automatically. It saves time, reduces errors, and updates instantly when your data changes.

Before vs After

✗ Before

Copy column -> Paste in new column -> Manually delete unwanted parts

✓ After

Split Column by Delimiter -> Merge Columns with Separator

What It Enables

You can clean and reshape your data effortlessly, making your reports clearer and more useful.

Real Life Example

A sales manager receives a list where customer full names and phone numbers are in one column. Using splitting, they separate names and numbers to analyze customer calls and sales separately.

Key Takeaways

Manual splitting and merging is slow and error-prone.

Power BI automates these tasks with simple clicks.

This makes data cleaning faster and reports more accurate.

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