Spring Boot Schema Diff — Compare Java Database Schemas Online

Spring Boot Schema Diff.
Compare JPA migrations.
Zero setup.

Paste two CREATE TABLE dumps from your Spring Boot app — whether from Flyway V1__init.sql, Liquibase changelog.xml, JPA ddl-auto=create output, or raw SQL. Spot every table, column, index, and constraint change instantly. Get ready-to-run ALTER TABLE scripts for MySQL or PostgreSQL — all in your browser.

No account required. No data leaves your device.

Built for Spring Boot & Java workflows

SchemaLens understands Java-specific patterns that generic diff tools miss.

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Flyway & Liquibase Review

Compare db/migration/V__*.sql outputs or Liquibase-generated DDL before and after entity changes. Verify that your migration scripts match the JPA schema exactly.

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JPA/Hibernate Entity Diff

Detects @Column(length=50) → @Column(length=100), @Temporal changes, and @Lob remappings. Warns when nullable=false additions break existing inserts.

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Index & Unique Constraint

Diffs @Table(indexes = ...), @Index, and @UniqueConstraint declarations. Catches missing indexes that could slow down Spring Data JPA queries.

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@ManyToOne & @JoinColumn

Validates @JoinColumn foreign keys and @ManyToOne / @OneToOne relationships. Detects missing or changed constraints that could break entity associations.

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Inheritance Strategy

Compares @Inheritance(strategy = JOINED), SINGLE_TABLE, and TABLE_PER_CLASS schemas. Detects discriminator column drift and subclass table changes.

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Privacy First

Your schema never leaves the browser. Compare production Spring Boot schemas safely without uploading sensitive table structures to a third-party server.

How it works with Spring Boot

Dump your schemas

Run mvn flyway:info or export DDL with spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create on both environments.

Paste into SchemaLens

Copy the SQL into the two editor panes. Dialect auto-detects MySQL, PostgreSQL, or SQL Server based on your spring.datasource.url.

Review the diff

See added tables, dropped columns, type changes, and constraint modifications highlighted in color. Check for breaking changes before your next ./mvnw deploy.

Copy the migration

Export ALTER TABLE scripts, save as Markdown for PR descriptions, or generate rollback SQL. Run in staging, then production.

Spring Boot migration examples

SchemaLens generates production-ready ALTER TABLE scripts for every change it detects.

Add a new column

ALTER TABLE users
  ADD COLUMN email_verified BOOLEAN DEFAULT FALSE;

Enlarge VARCHAR for JPA

ALTER TABLE products
  ALTER COLUMN description TYPE VARCHAR(2000);

Add a foreign key

ALTER TABLE orders
  ADD CONSTRAINT fk_orders_user_id
  FOREIGN KEY (user_id) REFERENCES users(id)
  ON DELETE CASCADE;

Add a unique constraint

ALTER TABLE users
  ADD CONSTRAINT uk_users_email
  UNIQUE (email);

Related guides

Java