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Mock Database Migration Generator

Used by developers, writers, and creators worldwide.

A mock database migration generator produces example SQL migration scripts for learning, prototyping, and documentation. Migrations are the versioned changes that evolve a database schema over time — creating tables, adding columns, building indexes — and writing them from scratch while you are learning, or to illustrate a concept, is fiddly. This generator gives you realistic migration scripts on demand, modelling the structure and SQL a real migration uses, so you can study the pattern, prototype a schema change, or document a workflow without composing each statement by hand. Treat the output as a learning aid and a starting point rather than a production migration, adapting the tables and columns to your database. Because it runs instantly in your browser for free, you can generate as many example migrations as you need, in different shapes, with no cost, signup, or limit.

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How to use

  1. Choose your options above
  2. Click Generate
  3. Copy your result

Detailed instructions

  1. Enter the exact table name you want to target in the Table Name field (e.g., 'orders' or 'user_profiles').
  2. Select the migration type from the dropdown — choose create-table, add-column, drop-column, rename-column, or create-index.
  3. Pick the SQL dialect that matches your database: PostgreSQL, MySQL, or SQLite.
  4. Click Generate to produce the migration script, then review the UP and DOWN sections for correctness.
  5. Copy the output and paste it into your migration file, adjusting column types or constraints to match your real schema.

Use Cases

  • •Learning how SQL migrations are structured
  • •Prototyping a schema change before writing it
  • •Illustrating migrations in a tutorial or doc
  • •Generating example scripts for a workshop
  • •Reminding yourself of common migration patterns

Tips

  • →When using create-table, immediately generate a matching create-index script for the same table to scaffold both files at once.
  • →For Flyway projects, generate the DOWN script as a separate undo migration file prefixed with U instead of V.
  • →SQLite's DROP COLUMN output should be tested against your SQLite version — versions below 3.35.0 require a table-rebuild workaround instead.
  • →Use the rename-column operation to generate the syntax reference, then manually add a data migration step if the column holds values that need transforming.
  • →MySQL users: the generated scripts assume InnoDB; add ENGINE=InnoDB explicitly if your database defaults to MyISAM to ensure transaction support.
  • →Generate the same operation in all three dialects and diff the output to build a personal reference for cross-database syntax differences.

FAQ

what is a database migration

A migration is a versioned script that changes a database schema — creating a table, adding a column, building an index — so the schema can evolve in a controlled, repeatable way across environments. Migrations are run in order, and each is a discrete, reversible step in the database's history.

is the generated migration ready to run

It is a realistic example for learning and prototyping, not a production migration. SQL dialects differ between databases, so review the statements, adapt the tables and columns to your schema, and test against your target database before running anything for real.

why use migrations instead of changing the database directly

Migrations record every schema change as code, so the database can be rebuilt identically across development, testing, and production, and changes can be reviewed and rolled back. Editing a database directly loses that history and makes environments drift apart, which migrations exist to prevent.