PQ combine columns with conditions

[SOQLee]

In Power Query, how do you combine Columns 1 and 2 to produce Column 3 as in the example below. The value 999999999 is stored as text.

Col1	Col2	Col3
999999999	999999999	999999999
null	#N/A	null
999999999	#N/A	999999999
null	999999999	999999999

<colgroup><col><col><col></colgroup><tbody>
</tbody>

 

[Matt Allington]

You can add a new column with an if statement. You need to know the rules of course.

The syntax is (case sensitive)

= if column1 = something then column1 else column2