SQLite Database Merge Tool with Flask and Python

A Flask-based web application for merging SQLite databases. This tool helps you copy tables and data between production and development databases while preserving constraints and schema information.

Features

• Database Comparison: View tables from source and destination databases side-by-side
• Schema Inspection: View detailed table information including:
  • Column definitions (name, type, constraints)
  • Primary keys
  • Foreign keys
  • Indexes
  • Full CREATE TABLE schema
• Structure Copying: Copy table structure (schema) from source to destination
• Data Copying: Copy table data with two modes:
  • Replace: Delete existing data and insert new data
  • Append: Add data to existing records
• Constraint Detection: Automatically identifies constraints that need to be copied
• Data Preview: View first 100 rows of any table

Installation

1. Install dependencies:

pip install -r requirements.txt

2. Create database directories (already created):

databases/
  source/      # Place source databases here
  destination/ # Place destination databases here

Usage

1. Start the Flask application:

python app.py

2. Open your browser to http://localhost:5000

3. Place your SQLite databases in the appropriate directories:

   • Source databases → databases/source/
   • Destination databases → databases/destination/

4. Use the web interface to:

   • Select source and destination databases
   • Choose tables to merge
   • View table information and constraints
   • Copy structure and/or data

Workflow

1. Select Databases: Choose source and destination databases from dropdowns
2. Choose Table: Select a table from the source database
3. Review Info: Examine table structure, constraints, and row count
4. Copy Structure: If the table doesn't exist in destination, copy the structure first
5. Copy Data: Choose replace or append mode and copy the data

API Endpoints

• GET /api/databases - List available databases
• GET /api/tables/<db_type>/<db_name> - List tables in a database
• GET /api/table-info/<db_type>/<db_name>/<table_name> - Get table schema and constraints
• GET /api/table-data/<db_type>/<db_name>/<table_name> - Get table data (max 100 rows)
• POST /api/copy-structure - Copy table structure
• POST /api/copy-data - Copy table data

Safety Features

• Confirmation prompts before destructive operations
• Clear indication of replace vs. append modes
• Constraint validation before data copying
• Row count display to understand data volume

Tech Stack

• Backend: Flask, Python, SQLite3
• Frontend: Tailwind CSS, DaisyUI, Vanilla JavaScript
• Database: SQLite

Notes

• The tool works by reading databases from separate directories (not loading into memory)
• Foreign key constraints are displayed but must be satisfied in the destination database
• Indexes are created automatically when copying structure
• Maximum 100 rows are displayed in data preview (all rows are copied during merge)