Only declared relationships appear
Foreign-key clauses produce relationship lines. Similar names such as user_id never create an inferred edge.
- Input
- SQL
- Dialects
- 4 explicit
- Runtime
- Browser
Turn supported SQL DDL into Mermaid ER syntax
Generate Mermaid erDiagram text from the narrow CREATE TABLE model without querying a catalog.
Local processingNo sign-upNever executed
Create Mermaid ERD
Inputs stay in this browser tab. Parser-heavy work uses a tighter 256 KiB safety cap.
Mermaid ER source
No result is placed in a URL, account, API, or remote log.
What this tool does
Bounded, explicit-dialect processing
The diagram reflects only pasted declarations accepted by the converter. It does not infer relationships from naming conventions or inspect indexes and live constraints.
Diagram identifiers are sanitized
Names are converted to safe Mermaid identifiers while the source DDL remains unchanged.
The parser runs locally under byte, statement, AST-node, depth, row, column, diagnostic, and output limits. It never connects to a database or resolves files and URLs.
Primary references
Questions and answers
Related SQL tools
SQL DDL to JSONExtract tables, ordinary columns, primary-key flags, nullability, and declared foreign keys from supported DDL.SQL Schema ComparatorExtract the same narrow schema model from two DDL inputs and compare their tables, columns, and foreign keys.SQL Syntax ValidatorParse one explicit SQL dialect and report syntax status, statement count, and statement types.