Online SQL to JSON Converter: Quickly Transform Queries and Schemas

When developing web applications and integrating systems, there is often a need to migrate data from relational databases (SQL) to JSON, the standard for modern APIs and NoSQL solutions. Our free online tool is designed to instantly convert SQL dumps, INSERT INTO statements, and CREATE TABLE definitions into structured JSON objects or JSON Schemas.

This converter helps front-end developers quickly create data mocks, and back-end engineers – Generate validation schemas based on existing table structures without writing complex parsing code.

Why convert SQL to JSON?

SQL and JSON represent data differently: the former focuses on tables and relationships, while the latter focuses on hierarchical objects. Conversion is necessary in the following cases:

Data Migration: Migrating seed data from PostgreSQL or MySQL to MongoDB or Firebase.
API Creation: Generating sample server responses based on real database data.
Validation: Generating JSON Schema from an SQL query to automatically validate incoming data in Node.js or Python.
Prototyping: Quickly obtaining an array of objects for rendering interfaces without connecting to a live database.

How to Use the Tool

The tool works entirely client-side, ensuring the security of your data—it is not transmitted to the server. To get started, follow a few simple steps:

Paste the code: Copy the SQL query (INSERT or CREATE) into the left window or upload a file with the .sql extension.
Select mode:
- Template: Creates an array of objects with data or an empty template based on the table structure.
- JSON Schema: Generates a validation schema describing data types and required fields.
Customize the output: Use the Pretty print option to format JSON beautifully.
Get the result: Copy the resulting JSON or download it as a file .json.

Conversion examples

1. Converting INSERT INTO to an Array of Objects

If you paste data in INSERT format, the tool will create an array of objects where the keys correspond to the column names.

copy
INSERT INTO employees (id, name, position, salary)
VALUES
(1, 'Alexey Ivanov', 'Senior Developer', 250000),
(2, 'Maria Sidorova', 'QA Engineer', 180000);

Conversion result:

copy
[
{
"id": 1,
"name": "Alexey Ivanov",
"position": "Senior Developer",
"salary": 250000
},
{
"id": 2,
"name": "Maria Sidorova",
"position": "QA Engineer",
"salary": 180000
}
]

2. Generating JSON Schema from CREATE TABLE

When using the "JSON Schema" mode, the tool parses SQL data types (INT, VARCHAR, BOOLEAN) and maps them to JSON types (number, string, boolean).

Copy
CREATE TABLE products (
id INTEGER PRIMARY KEY,
title VARCHAR(255),
price DECIMAL(10, 2),
in_stock BOOLEAN
);

Result (Schema):

copy
{
"type": "object",
"properties": {
"id": { "type": "integer" },
"title": { "type": "string" },
"price": { "type": "number" },
"in_stock": { "type": "boolean" }
},
"required": ["id", "title", "price", "in_stock"]
}

Key advantages of our service

Our converter is This isn't just a text replacement, but an intelligent parser that takes into account the specifics of SQL syntax:

Intelligent type detection: Automatically recognizes numbers, strings, Boolean values, and NULL.
Comment support: Correctly handles escaping, as well as table and field names in backticks (` `), double quotes (" "), or square brackets ([ ]).
Comment handling: Ignores SQL comments (-- and /* */), preventing errors in JSON.
MultipleNatural tables: If the SQL code describes multiple tables, the tool will group them into a single JSON object.

Frequently Asked Questions (FAQ)

Does the tool support large SQL files?

Yes, you can upload SQL dumps up to several megabytes in size. Since processing occurs in your browser, the speed depends only on the performance of your device.

Is it safe to insert sensitive data?

Absolutely. The entire conversion process is performed locally. Data is not sent to our server or stored in logs.

Which SQL dialects are supported?

The parser is oriented towards the SQL-92 standard and handles MySQL, PostgreSQL, SQLite, and MS SQL Server syntax well for INSERT and CREATE TABLE commands.

How are NULL values handled in SQL?

NULL values in SQL queries are correctly converted to the corresponding null in JSON format.

Can I get a JSON Schema from a regular INSERT?

Yes, switch to "JSON Schema" mode. The tool will analyze the values in your INSERT statement and output the most appropriate data schema.

SQL to JSON