Categories

Database Schema Diff

Compare two database schemas and generate migration-oriented change reports

Compare two database schemas to identify table, column, index, and foreign key changes.

Supported inputs

  • SQL DDL
  • JSON or YAML schema summaries

Outputs

  • Structured diff report
  • Migration SQL draft
  • Visualization-friendly graph data

Example Results

2 examples

Compare SQL DDL and draft a PostgreSQL migration

Show how a schema gains a new required column and index, then generate the matching migration SQL.

{
  "summary": {
    "tablesAdded": 0,
    "tablesRemoved": 0,
    "columnsAdded": 1,
    "columnsRemoved": 0,
    "columnsChanged": 0,
    "indexesChanged": 1,
    "foreignKeysChanged": 0,
    "totalChanges": 2
  },
  "migrationSQL": "ALTER TABLE users ADD COLUMN email TEXT NOT NULL;\nCREATE INDEX idx_users_email ON users (email);"
}
View input parameters
{ "sourceSchema": "CREATE TABLE users (\n id INT PRIMARY KEY,\n name TEXT\n);", "targetSchema": "CREATE TABLE users (\n id INT PRIMARY KEY,\n name TEXT,\n email TEXT NOT NULL\n);\nCREATE INDEX idx_users_email ON users (email);", "schemaFormat": "sql", "dialect": "postgresql" }

Diff JSON schemas with SQLite-style removal warnings

Compare JSON schema summaries where one table and one column are removed, including the SQLite rebuild note.

{
  "summary": {
    "tablesRemoved": 1,
    "columnsRemoved": 1
  },
  "migrationSQL": "DROP TABLE audit_logs;\n-- SQLite requires table rebuild to drop column users.email"
}
View input parameters
{ "sourceSchema": "{\n \"tables\": {\n \"users\": {\n \"columns\": {\n \"id\": {\n \"type\": \"INTEGER\",\n \"primaryKey\": true,\n \"nullable\": false\n },\n \"email\": {\n \"type\": \"TEXT\",\n \"nullable\": false\n }\n }\n },\n \"audit_logs\": {\n \"columns\": {\n \"id\": {\n \"type\": \"INTEGER\",\n \"primaryKey\": true,\n \"nullable\": false\n }\n }\n }\n }\n}", "targetSchema": "{\n \"tables\": {\n \"users\": {\n \"columns\": {\n \"id\": {\n \"type\": \"INTEGER\",\n \"primaryKey\": true,\n \"nullable\": false\n }\n }\n }\n }\n}", "schemaFormat": "json", "dialect": "sqlite" }

Key Facts

Category
Development
Input Types
textarea, select
Output Type
json
Sample Coverage
4
API Ready
Yes

Overview

Database Schema Diff compares two schema definitions and turns the gap into a migration-oriented report covering tables, columns, indexes, and foreign keys.

When to Use

  • When you need to understand how one database schema differs from another.
  • When release planning depends on knowing which DDL changes are required.
  • When teams want a migration draft before applying changes in MySQL, PostgreSQL, or SQLite.
  • When reviewing schema updates in pull requests or handoff documents.

How It Works

  • Paste the current schema and the target schema in SQL DDL or JSON/YAML summary form.
  • The tool parses tables, columns, indexes, and foreign keys from each side.
  • It compares added, removed, and changed elements between the two versions.
  • The output includes a structured change list, a migration SQL draft, and visualization-ready relationship data.

Use Cases

Planning a production migration for a backend release.
Reviewing whether a schema change introduces breaking column updates.
Preparing a handoff report between development and DevOps teams.
Comparing generated schemas from different branches or environments.

Examples

1. Review a schema migration before deployment

Backend engineer
Background
A service branch adds new audit tables and updates user columns before a release.
Problem
The team needs a clear summary of what will change in production.
How to Use
Paste the current and target DDL, select the database dialect, and inspect the change list plus migration SQL.
Example Config
Schema format: Auto Detect. Dialect: PostgreSQL.
Outcome
The team gets a concise diff report with table, column, index, and foreign key changes plus a SQL draft.

Try with Samples

sql

Related Hubs

FAQ

What input formats are supported?

You can provide SQL DDL or JSON/YAML schema summaries. The tool auto-detects the format when possible.

Does it generate migration SQL?

Yes. It produces a draft migration script that can serve as a starting point for review and refinement.

Which databases are targeted?

The tool is designed around MySQL, PostgreSQL, and SQLite style schema changes.

Can it show relationship changes too?

Yes. Foreign key additions and removals are included, along with graph-friendly relation data.

API Documentation

Request Endpoint

POST /en/api/tools/database-schema-diff

Request Parameters

Parameter Name Type Required Description
sourceSchema textarea Yes -
targetSchema textarea Yes -
schemaFormat select No -
dialect select No -

Response Format

{
  "key": {...},
  "metadata": {
    "key": "value"
  },
  "error": "Error message (optional)",
  "message": "Notification message (optional)"
}
JSON Data: JSON Data

AI MCP Documentation

Add this tool to your MCP server configuration:

{
  "mcpServers": {
    "elysiatools-database-schema-diff": {
      "name": "database-schema-diff",
      "description": "Compare two database schemas and generate migration-oriented change reports",
      "baseUrl": "https://elysiatools.com/mcp/sse?toolId=database-schema-diff",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

You can chain multiple tools, e.g.: `https://elysiatools.com/mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp`, max 20 tools.

If you encounter any issues, please contact us at [email protected]