Excel to SQLite Importer

A fast, lightweight desktop tool to import Excel files (.xlsx / .xls) into a SQLite database. Built with Python and Tkinter — no browser, no internet, no installation required (when using the .exe).

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Features

• Import multiple Excel sheets into a single SQLite table called Data
• Choose where to save the .db file using a standard Save As dialog
• Performance presets to match your PC's RAM and CPU
• Real-time progress bar showing current sheet and total row count
• Stop button to cancel import at any time
• Live log console inside the app
• Works as a standalone .exe — no Python needed on target machines

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Screenshots

UI includes: Excel file picker, Save location picker, Performance preset dropdown, Start/Stop buttons, Progress bar, and log console.

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Requirements

If running from source:

Python 3.8+
openpyxl

Install dependency:

pip install openpyxl

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Running from Source

python excel_to_sqlite.py

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Building the .exe

Install PyInstaller:

pip install pyinstaller

Build the executable:

pyinstaller --onefile --windowed --name "ExcelToSQLite" excel_to_sqlite.py

The .exe will be output to:

dist\ExcelToSQLite.exe

No Python installation is required on the machine running the .exe.

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How to Use

1. Browse — Select your Excel file (.xlsx or .xls)
2. Save As — Choose where to save the output .db file and give it a name
3. Preset — Pick a performance level based on your PC specs
4. START — Begin the import
5. STOP — Cancel at any time (data inserted so far is saved)

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Performance Presets

Preset	Batch Size	Cache	Recommended For
Low	500 rows/tx	16 MB	Old PCs, 2GB RAM
Medium	2,000 rows/tx	32 MB	Average office PCs, 4–8GB RAM
High	5,000 rows/tx	64 MB	i5 / 16GB+ RAM
Ultra	10,000 rows/tx	128 MB	i7–i9 / 32GB+ RAM

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Database Structure

All sheets from the Excel file are merged into a single table named Data.

• The first row of each sheet is treated as column headers
• An id column is automatically added as PRIMARY KEY AUTOINCREMENT
• All columns are stored as NVARCHAR
• Column names are sanitized to be valid SQL identifiers

Example

Given an Excel file with this structure:

SERIES_NUMBER	IMAGE_NUMBER	LINE	NAME	TYPE
d_001	img_001	1	Martha	GIVENNAME

The resulting SQLite table Data will look like:

id	SERIES_NUMBER	IMAGE_NUMBER	LINE	NAME	TYPE
1	d_001	img_001	1	Martha	GIVENNAME

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SQLite Speed Optimizations Applied

The following SQLite PRAGMAs are used internally for maximum import speed:

PRAGMA journal_mode = WAL        -- Write-Ahead Logging for faster writes
PRAGMA synchronous  = OFF        -- Skip fsync calls (biggest speed gain)
PRAGMA cache_size   = -N         -- Large in-memory page cache
PRAGMA temp_store   = MEMORY     -- Temp tables stored in RAM
PRAGMA locking_mode = EXCLUSIVE  -- No per-write lock overhead

Combined with large batch executemany() inserts inside explicit BEGIN / COMMIT transactions.

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Notes

• The sqlite_sequence table that appears in SQLite viewers is automatically created by SQLite to track AUTOINCREMENT counters. It is not your data — ignore it.
• If the app is closed during import, the current batch is finished before the window closes.
• Re-running the import on an existing .db file will append rows to the existing Data table. Delete the .db file first if you want a fresh import.

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Project Structure

excel_to_sqlite.py   # Main application source
README.md            # This file
dist/
  ExcelToSQLite.exe  # Built executable (after running PyInstaller)

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License

MIT License. Free to use, modify, and distribute.