Merging Tables in Power Query

Sure! Here's a succinct Power Query M code snippet that merges two tables based on two or more columns and returns only matching records:

let
    // Source tables
    table1 = #table({"Key1", "Key2", "Column1"}, {{1, "A", "Value1"}, {2, "B", "Value2"}}),
    table2 = #table({"Key1", "Key2", "Column2"}, {{1, "A", "Value3"}, {3, "C", "Value4"}}),

    // Merge tables
    mergedTable = Table.Join(table1, {"Key1", "Key2"}, table2, {"Key1", "Key2"}),

    // Select columns to keep in the final result
    resultTable = Table.SelectColumns(mergedTable,{"Key1", "Key2", "Column1", "Column2"})
in
    resultTable

This code creates two source tables (table1 and table2) with matching and non-matching records. The tables are then merged using the Table.Join function, specifying the key columns (Key1 and Key2) in both tables. Finally, the Table.SelectColumns function is used to select the desired columns (Key1, Key2, Column1, and Column2) in the result table.

Example usage:

• table1:

| Key1 | Key2 | Column1 |
|------|------|---------|
|  1   |  A   | Value1  |
|  2   |  B   | Value2  |

• table2:

| Key1 | Key2 | Column2 |
|------|------|---------|
|  1   |  A   | Value3  |
|  3   |  C   | Value4  |

• Result (resultTable):

| Key1 | Key2 | Column1 | Column2 |
|------|------|---------|---------|
|  1   |  A   | Value1  | Value3  |

The resulting table contains only the matching records based on the Key1 and Key2 columns.