Merging and Appending Queries

Combining data from multiple tables is one of the most powerful features of Power Query. There are two main operations: Merge (join horizontally) and Append (stack vertically).

Merge Queries (Horizontal Join)

Merging combines columns from two tables based on a matching column — similar to SQL JOINs.

Steps:

1. In Power Query, click Home → Merge Queries
2. Select the primary table (the one you're adding columns to)
3. Select the secondary table (the one with additional columns)
4. Click the matching column(s) in both tables
5. Choose the Join Kind
6. Click OK
7. Expand the merged column to select which columns to add

Join Types

Merge Example

Table A (Orders): OrderID, CustomerID, Amount Table B (Customers): CustomerID, CustomerName, City

Merge on CustomerID using Left Outer Join → Result includes all orders with customer names and cities.

Append Queries (Vertical Stack)

Appending stacks rows from two or more tables on top of each other — like SQL UNION.

Pre-requisite: Tables must have the same column structure (same number and names of columns).

Steps:

1. In Power Query, click Home → Append Queries
2. Choose:

• Two Tables: Append one table to the current query
• Three or More Tables: Select multiple tables to append

1. Click OK

Append Example

Q1 Sales: Date, Product, Revenue (Jan-Mar data) Q2 Sales: Date, Product, Revenue (Apr-Jun data)

Append → Result: A single table with all 6 months of data.

Merge vs Append