Combine Sheets & Files in OpenOffice Calc: Tips for Joining Multiple Spreadsheets into One

• Open a list of files in a folder.
• For each file: open, copy used range, paste into destination file below the last used row, close source.
• Optionally append a column with source filename.

Example (conceptual pseudocode):

for each file in folder:   open file   select used range   copy   paste into target at next empty row   add filename into Source column for those rows   close file end for 

Macro tips:

• Test on copies first.
• Handle headers: paste headers only once.
• Add error handling for protected files or differing formats.

Method 6 — Use CSV as an intermediary for heterogenous sources

If you have mixed file formats or need to import from other spreadsheet apps:

1. Export each sheet/file to CSV with consistent column order.
2. In the target Calc file, use Sheet → Insert → Sheet From File or Data → Text to Columns to import CSVs.
3. Stack CSVs into one sheet by appending below the last row.

CSV approach is robust for data-only merges and is often faster for very large datasets.

Handling duplicates and conflicts

• Use Data → Filter → Standard Filter to find duplicates or criteria-based rows.
• Use Data → More Filters → Advanced Filter for complex deduplication.
• Create a helper column that concatenates key fields (e.g., =A2&B2&C2) and remove duplicates based on that.
• Consider using Pivot Tables to summarize and check for unexpected duplicates before deleting.

Dealing with formulas and references after merging

• If you pasted values but want formulas recalculated, use Paste Special → Formulas.
• If you need references to update to the new sheet locations, adjust formulas with Find & Replace or use relative references before copying.
• Consider converting formulas to values (Paste Special → Values) when you want a static combined dataset.

Performance considerations

• Very large combined sheets may slow Calc. Split very large datasets into multiple sheets or use a database (Base) if you need heavy querying.
• Reduce volatile functions (INDIRECT, NOW, RAND) in combined workbooks.
• Save frequently and use compressed .ods format.

Checklist before finalizing

• Verify headers are consistent and present only once.
• Confirm data types and date formats match.
• Ensure sum totals or key metrics reconcile with original files.
• Remove or document external links.
• Save a final backup and version the combined file (e.g., Combined_2025-08-30.ods).

Quick troubleshooting

• Pasted data appears misaligned: check hidden columns/rows and matching column order.
• Links show #REF!: file moved or sheet renamed—update path or recreate links.
• Macro fails on permissions: enable macros and check file protections.

Combining sheets and files in OpenOffice Calc can be as simple as copy-and-paste or as powerful as a scripted automation depending on your needs. Standardize your data, pick the right method for the job, and test on backups.