Which SQL dialects are supported?

It handles the common subset of MySQL, PostgreSQL and SQLite CREATE TABLE syntax — quoted or unquoted identifiers, column types with size and precision, NOT NULL, DEFAULT and inline PRIMARY KEY. Vendor-specific extensions are ignored gracefully rather than failing.

How are SQL types mapped to JSON Schema?

Integer types map to integer, numeric and floating types to number, text and character types to string with maxLength where a size is given, boolean to boolean, and date/time types to string with the appropriate format (date or date-time). Unknown types fall back to string.

How does it decide which fields are required?

A column becomes a required property when it is declared NOT NULL or is the PRIMARY KEY, and does not have a DEFAULT that would let it be omitted on insert. Nullable columns are optional.

Does it handle multiple tables at once?

Yes. Paste several CREATE TABLE statements and each one becomes its own JSON Schema object or TypeScript interface, named after the table.

Is my SQL sent anywhere?

No. The parser and generator run entirely in your browser. Your schema and any sensitive column names never leave your device.

SQL CREATE TABLE to JSON Schema

Converting a database schema into a JSON Schema or TypeScript interface by hand is tedious and error-prone. This tool parses your CREATE TABLE DDL and produces a faithful structural definition you can drop straight into validation middleware, API contracts or typed clients — all in the browser, so proprietary schemas stay private.

How it works

The converter tokenises each CREATE TABLE name ( … ) statement and splits the body on top-level commas (respecting parentheses so DECIMAL(10,2) isn’t broken apart). For every column definition it extracts:

The name (with surrounding `, " or [] quotes stripped).
The type and any size/precision, e.g. VARCHAR(255), DECIMAL(10,2).
Constraints — NOT NULL, DEFAULT …, inline PRIMARY KEY.

It then maps each SQL type to its JSON-Schema equivalent:

INT/BIGINT/SMALLINT/SERIAL  -> integer
DECIMAL/NUMERIC/FLOAT/REAL  -> number
VARCHAR/TEXT/CHAR/UUID      -> string (maxLength from the size)
BOOLEAN/BOOL/TINYINT(1)     -> boolean
DATE                        -> string, format: date
TIMESTAMP/DATETIME          -> string, format: date-time

A column is added to the schema’s required array when it is NOT NULL or the primary key and has no DEFAULT. For TypeScript output, nullable columns become optional (name?: type).

Tips and notes

Lines that are table-level constraints (PRIMARY KEY (...), FOREIGN KEY (...), CONSTRAINT …, INDEX …) are detected and skipped — they aren’t columns.
An unrecognised type falls back to string so the output is always valid.
TINYINT(1) is treated as boolean to match the common MySQL convention.
The generated JSON Schema uses draft-07 ($schema, type: object, properties, required).