Oracle Schema Diff Online — Compare & Migrate Oracle Schemas

Oracle Schema Diff.
Generate migrations.
Zero setup.

Paste two DBMS_METADATA.GET_DDL outputs or schema exports. Spot every table, column, index, and constraint change instantly. Get ready-to-run ALTER TABLE scripts for Oracle — all in your browser.

No account required. No data leaves your device.

Built for Oracle workflows

SchemaLens understands Oracle-specific syntax that generic diff tools miss.

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IDENTITY & Sequence Columns

Correctly detects GENERATED ALWAYS AS IDENTITY and GENERATED BY DEFAULT AS IDENTITY changes across schema versions.

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Oracle Data Types

Handles VARCHAR2, NVARCHAR2, NUMBER(p,s), CLOB, NCLOB, BLOB, TIMESTAMP, and RAW with precision.

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Constraints & Indexes

Primary keys, unique constraints, foreign keys, CHECK constraints, and bitmap indexes — all compared semantically, not by raw text.

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Quoted Identifiers

Handles double-quoted identifiers ("User") and mixed-case table names exactly like Oracle does.

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Tablespace & Storage Clauses

Gracefully skips TABLESPACE, STORAGE, PCTFREE, and other physical storage clauses so they don't break parsing.

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Privacy First

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

How it works

Export your schemas

Run DBMS_METADATA.GET_DDL('TABLE', 'TABLE_NAME') or use SQL Developer to export schema DDL for both databases.

Paste into SchemaLens

Copy the SQL into the two editor panes. Dialect is automatically set to Oracle.

Review the diff

See added tables, dropped columns, type changes, and constraint modifications highlighted in color.

Copy the migration

Export ALTER TABLE scripts, save as Markdown, PDF, or raw SQL. Run in staging, then production.

Oracle migration examples

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

Column type change

ALTER TABLE "users"
  MODIFY ("bio" VARCHAR2(500));

Add a new column

ALTER TABLE "orders"
  ADD "shipped_at" TIMESTAMP;

Add a foreign key

ALTER TABLE "comments"
  ADD CONSTRAINT "fk_comments_post"
  FOREIGN KEY ("post_id") REFERENCES "posts"("id");

Set a default value

ALTER TABLE "tasks"
  MODIFY ("status" DEFAULT 'pending');

Related guides

Oracle