SQL Schema Visualizer
Paste SQL DDL to visualize tables, columns, and explicit foreign-key relationships with links back to the source.
SQL Schema Visualizer
Paste SQL DDL to visualize tables, columns, and explicit foreign-key relationships with links back to the source.
About SQL schema visualization
Connect each diagram item to its DDL source
The visualizer parses the pasted DDL into tables, columns, keys, and explicit foreign-key relationships. Selecting a table or relationship reveals the exact source lines that produced it.
Supported DDL scope
This version supports CREATE TABLE, inline and table-level PRIMARY KEY and UNIQUE constraints, REFERENCES and FOREIGN KEY declarations, ALTER TABLE ADD foreign keys, quoted or schema-qualified identifiers, and composite keys. Other clauses are reported in diagnostics.
DDL stays in your browser
Parsing, diagram generation, Mermaid conversion, and SVG export run in your browser. The tool does not upload the DDL or generated diagram.
FAQ
Common questions and answers about this topic.
How do I turn SQL DDL into a schema diagram?
Paste CREATE TABLE or supported ALTER TABLE statements into the editor. The tool parses them immediately and draws each table, column, key, and declared foreign-key relationship.
Which SQL syntax is supported?
The visualizer supports a bounded DDL subset across common MySQL, PostgreSQL, and SQLite forms. It recognizes CREATE TABLE, common key constraints, explicit references, ALTER TABLE ADD foreign keys, quoted names, schema-qualified names, and composite keys.
How are table relationships detected?
Only REFERENCES and FOREIGN KEY declarations create relationships. Similar column names such as user_id do not create a link unless the DDL explicitly declares one.
What happens to unsupported SQL syntax?
Supported declarations remain visible, while unsupported statements or clauses appear in diagnostics with their source range. They are not silently interpreted as a different construct.
Can I export the schema diagram?
Yes. Copy the generated Mermaid ER diagram source for documentation or download the rendered diagram as SVG.
Is my database schema uploaded?
No. DDL parsing, diagram generation, Mermaid conversion, and SVG export run locally in your browser.