JSON to SQL DDL Generator
Convert raw JSON objects into structured SQL DDL statements instantly. Generate clean CREATE TABLE scripts directly in your browser with Doffl for free.
About JSON to SQL DDL
The JSON to SQL DDL generator converts sample JSON objects or arrays into executable SQL CREATE TABLE scripts. It automatically inspects your data structure, infers appropriate column data types such as integers, booleans, and varchars, and outputs clean table definitions in seconds.
Designed for backend developers, data engineers, and system architects migrating API payloads to relational databases. All conversions run locally inside your browser, keeping your data confidential without requiring account creation.
Key features
- Automatic column data type inference from JSON values
- Generates standard SQL CREATE TABLE statements instantly
- Supports single JSON objects and arrays of records
- Configurable target table name and column naming rules
- Client-side processing ensures complete payload privacy
- Free to use without account creation or installation
How to use JSON to SQL DDL
- Paste your JSON payload into the input editor.
- Specify your target table name and database dialect.
- Review the automatically mapped column types and constraints.
- Click Generate to produce the SQL DDL statements.
- Copy the generated CREATE TABLE script to your clipboard.
Who is it for?
- Backend developers modeling database schemas from third-party REST API responses.
- Data engineers generating relational staging tables for bulk JSON data pipelines.
- Engineers migrating document-based NoSQL collections to relational databases.
- Database administrators testing schema generation from sample payloads.
Frequently asked questions
How does the tool infer SQL data types from JSON?
The generator inspects the primitive values of each JSON key, mapping numeric values to integers or decimals, booleans to boolean columns, and strings to varchar or text types based on observed length.
Is my JSON payload sent to a server?
No. The entire conversion process runs directly in your web browser, ensuring that sensitive data payloads never leave your local machine.
Which SQL dialects are supported?
The generated DDL uses standard ANSI SQL syntax, making it directly compatible with PostgreSQL, MySQL, SQLite, MariaDB, and Microsoft SQL Server.
How does the generator handle nested JSON objects?
Nested objects can be mapped to JSON or JSONB column types in supported dialects, or flattened into related table definitions depending on your chosen configuration.
Is this JSON to SQL DDL tool free?
Yes. The tool is completely free to use with no daily limits, software installations, or account registrations required.