Compare lists / Blog

Notes on comparing lists

Small, worked examples for the problems that turn a quick comparison into an afternoon in a spreadsheet.

1. Compare two lists with duplicates: check occurrence counts

   Compare two lists with duplicates without losing repeated IDs. Work through a 4-versus-2 example, inspect source rows, and export a count difference report.

2. Compare CSV files without losing leading zeros in IDs

   Keep employee IDs and long identifiers as text when comparing CSV files. Learn where leading zeros disappear and choose an export that preserves the values.

3. Compare CSV files with different column order and headers

   Compare CSV files with different column order by choosing the matching key on each side. Check headers, separators, empty IDs, and the scope of each export.

4. Compare two lists and keep original rows in the result

   Keep the original rows when comparing two lists, so missing IDs still have their names, locations, and references. Inspect duplicate records and export context.

5. Why identical-looking values do not match in two lists

   Find why identical-looking values do not match: outer spaces, case, line breaks, Unicode, and mixed fields. Diagnose one pair before changing matching rules.

Compare two lists, or use the Excel formula guide to work in your spreadsheet.