# Database Schema Diff Compare two database schemas and generate migration-oriented change reports > Canonical page: https://elysiatools.com/en/tools/database-schema-diff - **Category:** Development - **Keywords:** database, schema, diff, migration, sql, ddl, postgres, mysql, sqlite ## Overview 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 ## Inputs - **Source Schema** (textarea): Paste the current schema SQL or JSON here... - **Target Schema** (textarea): Paste the desired schema SQL or JSON here... - **Schema Format** (select) - **Dialect** (select) ## When to use - Before deploying database changes to production to verify migration safety and completeness - When refactoring legacy schemas to track exactly which tables and columns are being modified - During code reviews to validate that proposed schema changes match the intended target structure ## How it works - Paste your current schema into the Source Schema field and the desired schema into the Target Schema field - Select the schema format (SQL DDL or JSON/YAML) and database dialect (MySQL, PostgreSQL, or SQLite) - The tool parses both schemas and compares tables, columns, indexes, and foreign key constraints - Review the structured diff report and copy the generated migration SQL draft to apply changes ## Use cases - Generate migration scripts when adding new tables or columns to an existing database - Audit schema drift between development and production environments - Document structural changes during database refactoring or deprecation projects ## Frequently asked questions ### What schema formats are supported? SQL DDL statements, JSON, or YAML schema summaries. ### Which database dialects are supported? MySQL, PostgreSQL, and SQLite, with auto-detection available. ### Does it detect foreign key changes? Yes, it identifies added, removed, or modified foreign key constraints in the diff report. ### Can I use this for SQLite column removal? Yes, but the tool will note that SQLite requires table rebuilds for column drops. ### Is the generated migration SQL production-ready? It provides a draft that should be reviewed and tested in a staging environment before production deployment. ## Related tools - [Database Backup Generator](https://elysiatools.com/en/tools/database-backup-generator): Generate SQL backup scripts for database tables - [Database Migration Generator](https://elysiatools.com/en/tools/database-migration-generator): Generate SQL migration scripts for database schema changes - [Table Schema Generator](https://elysiatools.com/en/tools/table-schema-generator): Generate SQL table schema definitions - [CSV to Database Migration Planner](https://elysiatools.com/en/tools/csv-to-database-migration-planner): Infer a relational schema from CSV data and generate create-table plus ALTER migration plans for PostgreSQL, MySQL, SQLite, or SQL Server - [XLSX SQL Insert Generator](https://elysiatools.com/en/tools/xlsx-sql-insert-generator): Read Excel headers and rows to generate SQL INSERT statements for bulk loading - [SQL Dialect Bridge](https://elysiatools.com/en/tools/sql-dialect-bridge): Translate SQL between MySQL, PostgreSQL, SQLite, BigQuery, Snowflake, and Redshift — DDL, DML, functions and types, with UNSUPPORTED warnings - [SQL Explain Plan Visualizer](https://elysiatools.com/en/tools/sql-explain-plan-visualizer): Parse EXPLAIN / EXPLAIN ANALYZE output (PostgreSQL/MySQL/SQLite) into a cost tree, flag estimated-vs-actual row divergence, and suggest indexes - [SQL Query Builder](https://elysiatools.com/en/tools/sql-query-builder): Build simple SQL queries visually ## Samples - [MySQL Database Samples](https://elysiatools.com/en/samples/mysql-database-samples): Sample MySQL database scripts with various complexity levels from simple tables to enterprise ERP systems - [Android Database Java Samples](https://elysiatools.com/en/samples/android-database-java): Android Java database examples including SQLite connection, SQL queries, and transaction processing - [Android Database Kotlin Samples](https://elysiatools.com/en/samples/android-database-kotlin): Android Kotlin database examples including SQLite connection, SQL queries, and transaction processing - [macOS Database Objective-C Samples](https://elysiatools.com/en/samples/macos-database-objectivec): macOS Objective-C database examples including SQLite CRUD operations, queries, transactions, and connection management ## Related content - [Database Schema, Migration, and SQL Workflow Tools](https://elysiatools.com/en/hubs/database-schema-migration): Plan table schemas, generate SQL, compare database changes, validate relationships, and move spreadsheet data into database-ready formats in one hub. - [SQL Query Review, Performance, and Relational Integrity Tools](https://elysiatools.com/en/hubs/sql-query-review-performance-and-integrity): Review SQL before it reaches production: format queries, assemble joins, inspect EXPLAIN plans, catch injection patterns, validate foreign keys, and compare schema drift in one focused hub. - [File and Data Diff & Comparison Tools](https://elysiatools.com/en/hubs/file-data-diff-comparison-tools): Compare two files, payloads, schemas, or datasets side by side and highlight what changed — across text, JSON, CSV/Excel, PDF, images, audio, databases, APIs, and configs. - [JSON Schema, Mock Data, and API Fixture Generators](https://elysiatools.com/en/hubs/json-generate): Curated tools for JSON schema generation, mock payload building, and API fixture preparation in one hub.