Splitting and merging columns in Power BI - Cheat Sheet & Quick Revision

Recall & Review

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What does splitting a column mean in Power BI?

Splitting a column means breaking one column into two or more columns based on a delimiter or position. For example, splitting a full name into first and last names.

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How can you merge columns in Power BI?

You can merge columns by selecting two or more columns and combining their values into one column, often with a separator like a space or comma.

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Which Power BI feature helps you split columns easily without writing code?

The Power Query Editor has a 'Split Column' option that lets you split columns by delimiter, number of characters, or positions with a few clicks.

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What is a common delimiter used when splitting columns?

Common delimiters include spaces, commas, semicolons, or special characters like hyphens. For example, splitting 'John Doe' by space gives 'John' and 'Doe'.

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Why would you merge columns in a report?

Merging columns helps create a single combined value for easier reading or analysis, like combining first and last names into a full name.

Which Power BI tool lets you split columns without writing code?

A Power Query Editor

B DAX formula bar

C Report view

D Data view

Power Query Editor provides easy options to split columns by delimiter or position.

What happens when you merge two columns in Power BI?

A They create a new column combining both values

B One column deletes the other

C Columns are split into smaller parts

D Data types change automatically

Merging columns combines their values into a new single column.

Which delimiter would you use to split 'apple,banana,orange' into separate columns?

A Space

B Semicolon

C Hyphen

D Comma

The comma is the delimiter separating the fruits.

If you want to split a column by the first 3 characters, which method would you use?

A Split by delimiter

B Split by number of characters

C Merge columns

D Filter rows

Splitting by number of characters breaks the column at a fixed length.

What is a reason to split a column in your data?

A To delete unwanted data

B To combine multiple columns

C To separate combined data into parts

D To change data types

Splitting helps separate combined data like full names into first and last names.

Explain how you would split a full name column into first and last names in Power BI.

Think about how names are separated by spaces.

Describe the steps to merge two columns into one with a space separator in Power BI.

Merging combines values with a chosen separator.

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