JSON to SQL Converter

Paste a JSON array of objects and get a CREATE TABLE statement with inferred column types plus INSERT statements for MySQL, PostgreSQL, SQLite or SQL Server. Nested objects can be stored as JSON columns or flattened into separate columns.

Last updated: October 24, 2026

How to use the JSON to SQL Converter

1. Paste your JSON (an array of objects), upload a .json file, or click Sample.
2. Choose the SQL dialect and type the table name.
3. Decide how to handle nested data: keep it as a JSON column or flatten it into separate columns.
4. Set the options: rows per INSERT, CREATE/DROP TABLE, primary key, NOT NULL and transaction.
5. Copy or download the .sql file and run it in your database client.

Type mapping by dialect

A column containing values of different JSON types (for example numbers in some rows and strings in others) falls back to VARCHAR or TEXT so every value fits. null and missing keys always become SQL NULL. VARCHAR lengths are rounded up to 10, 20, 50, 100, 150 or 255 characters to leave a little room for longer values later.

Example

The JSON [{"id":1,"name":"Ann","tags":["a"]},{"id":2,"name":"O'Brien"}] with the PostgreSQL dialect produces:

CREATE TABLE "users" (
  "id" INTEGER NOT NULL,
  "name" VARCHAR(10),
  "tags" JSONB,
  PRIMARY KEY ("id")
);

INSERT INTO "users" ("id", "name", "tags") VALUES
  (1, 'Ann', '["a"]'),
  (2, 'O''Brien', NULL);

JSON column or flattened columns?

• JSON column keeps the original structure and suits data you mostly read back as a whole. PostgreSQL JSONB and MySQL JSON can still be queried with operators such as ->> and JSON_EXTRACT().
• Flatten turns nested objects into ordinary columns (address_city, address_zip), which is easier to index, filter and join. Arrays are still stored as JSON text because they can hold any number of items; for real one-to-many data, move them to a separate table.
• For millions of records, a bulk loader is faster than INSERT statements: PostgreSQL can load JSON lines with COPY, MySQL with LOAD DATA, and SQL Server can read JSON directly with OPENJSON.

Frequently asked questions

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