Excel-to-SQLite Import Utility

I work with a very large Excel workbook—about 800,000 rows—and opening it has become painfully slow. I need a small Windows-friendly executable that I can install locally (no separate runtimes or server components) and use to:

• Browse for any .xlsx file, read every row without dropping or corrupting data, and load the full set straight into a fresh SQLite database that the tool creates beside the original file.
• Present a lightweight GUI: one multiline textbox where I can type any valid SQL statement and a results pane/grid that shows the returned rows. No extra frills such as syntax highlighting or autocomplete are necessary; simplicity and speed are the priority.
• Ensure reliability—types, encodings, and special characters from the spreadsheet must survive the import exactly as they appear in Excel. Duplicate column names or mixed data types should be handled gracefully (e.g., automatic renaming or coercion with clear messaging).
• Package everything into a single-click installer or standalone .exe so I can copy it to other Windows 10/11 machines without fiddling with dependencies. Bundling the SQLite engine and whichever Excel-reading library you choose (e.g., EPPlus, ClosedXML, xlrd) is expected.

Acceptance criteria:
1. Import of the provided 800k-row test file completes in under five minutes on a typical laptop (i5, 8 GB RAM).
2. Row counts and sample cross-checks confirm zero data loss.
3. Any valid query entered in the textbox returns accurate results.
4. No external database or admin rights required beyond the initial install.

Feel free to use C#, Python (PyInstaller), Go, or any language you’re comfortable with—as long as the final deliverable meets the points above and runs natively on Windows.