Table.Combine Function in Power Query M (4 Easy Examples)

Table.Combine takes a list of tables and stacks their rows into one combined table, the way a UNION appends data. Available in Excel (Power Query), Power BI Desktop, and Power BI Service.

If you have the same kind of data split across several tables, like one table per month or per region, and you want them in a single table, this is the function you reach for.

Table of Contents

Syntax of Table.Combine Function

Table.Combine(tables as list, optional columns as any) as table

where

tables (required, list). The list of tables to stack, written inside {}. They are appended in the order you list them.
columns (optional, any). The set of columns the result should have, given as a list of names or a table type. Omit it and the result uses the union of all the input columns.

Returns: a single table whose rows are all the input rows stacked together. Columns are matched by name, and any column a table is missing is filled with null.

In plain terms, you hand it a list of tables and it returns one table with every row, one after another.

Example 1: Stack two tables of the same shape

You have two monthly order tables with the same columns and want them in one.

Here is the first query, JanOrders:

Product	Units
Notebook	12
Pen	30

And the second query, FebOrders:

Product	Units
Marker	18
Eraser	9

Put both tables in a list and combine them:

let
    Jan = Excel.CurrentWorkbook(){[Name="JanOrders"]}[Content],
    Feb = Excel.CurrentWorkbook(){[Name="FebOrders"]}[Content],
    Combined = Table.Combine({Jan, Feb})
in
    Combined

The rows from both tables are stacked in the order listed.

The result holds all four rows:

Product	Units
Notebook	12
Pen	30
Marker	18
Eraser	9

January’s rows come first, then February’s, because that is the order in the list.

Example 2: Combine more than two tables

The list can hold as many tables as you need, so you can stack three regions at once.

Here is NorthSales:

Rep	Deals
Asha	5
Ben	7

Here is SouthSales:

Rep	Deals
Carl	3

And here is WestSales:

Rep	Deals
Dana	8
Ed	2

List all three inside the {}:

let
    North = Excel.CurrentWorkbook(){[Name="NorthSales"]}[Content],
    South = Excel.CurrentWorkbook(){[Name="SouthSales"]}[Content],
    West = Excel.CurrentWorkbook(){[Name="WestSales"]}[Content],
    Combined = Table.Combine({North, South, West})
in
    Combined

Every row from all three tables lands in one table.

The result has all five rows:

Rep	Deals
Asha	5
Ben	7
Carl	3
Dana	8
Ed	2

There is no limit on how many tables you put in the list.

Example 3: Tables with different columns

When the tables do not share all their columns, the result keeps every column and fills the gaps.

Here is OnlineStock, which has an Item and a Color column:

Item	Color
Mug	Blue
Cap	Red

Here is StoreStock, which has Item and Price instead:

Item	Price
Bottle	15
Bag	25

Combine them as usual:

let
    Online = Excel.CurrentWorkbook(){[Name="OnlineStock"]}[Content],
    Store = Excel.CurrentWorkbook(){[Name="StoreStock"]}[Content],
    Combined = Table.Combine({Online, Store})
in
    Combined

Columns are matched by name, so the result has Item, Color, and Price.

Each row gets null where its table did not have that column:

Item	Color	Price
Mug	Blue	null
Cap	Red	null
Bottle	null	15
Bag	null	25

The online rows have no Price, and the store rows have no Color, so those cells come back as null.

Example 4: Duplicate rows are kept

Table.Combine only appends. It does not remove rows that appear in more than one table.

Here is ListA:

Member	Points
Liam	100
Noah	80

Here is ListB, where Noah shows up again with the same points:

Member	Points
Noah	80
Olivia	60

Combine the two lists:

let
    A = Excel.CurrentWorkbook(){[Name="ListA"]}[Content],
    B = Excel.CurrentWorkbook(){[Name="ListB"]}[Content],
    Combined = Table.Combine({A, B})
in
    Combined

Both copies of the Noah row stay in the result.

The duplicate survives:

Member	Points
Liam	100
Noah	80
Noah	80
Olivia	60

If you want to drop the repeat, wrap the result in Table.Distinct.

Things to keep in mind with Table.Combine

It appends, it does not join. This is a UNION (rows stacked on top of each other), not a lookup that matches rows side by side. To join tables on a key, use the Merge Queries command (Table.NestedJoin) instead.
The tables must be in a list. Wrap them in {}. Passing them as separate arguments throws Expression.Error: 2 arguments were passed to a function which expects 1.
Column order follows first appearance. The result lists columns in the order they first show up across the tables, so a column unique to a later table lands to the right of the shared ones. Pass the optional columns list if you need a specific order.

Performance and query folding

Appending file-based sources, like every CSV in a folder, is the most common use of Table.Combine, and that work runs locally rather than folding back to a server.

Even against a foldable source it generally does not fold, so on very large tables the append happens in Power Query’s engine. That is fine for typical workbook and folder data.

Common questions about Table.Combine

What is the difference between Table.Combine and Merge Queries?

Table.Combine appends rows, so the result gets taller (more rows, same columns). Merge Queries (Table.NestedJoin) matches rows on a key and brings columns side by side, so the result gets wider.

How do I combine every table in a folder?

Use the Folder connector to get a table of files, then append their contents with Table.Combine. The standard From Folder flow builds this step for you automatically.

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