Convert JSON to PGSQL
Upload a .json or .ndjson file and get back a PGSQL SQL script you can load straight into your database. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.
Click to upload or drag and drop
CSV, Excel, SQLite, SQL, DBF (max 10 MB)
How your data is typed in PGSQL
Generated from the converter's own PGSQL type mapping — this is what it actually emits, not an example.
| Your data | PGSQL type |
|---|---|
| Whole number | BIGINT |
| Decimal (money) | NUMERIC(10,2) |
| Floating point | DOUBLE PRECISION |
| True / false | BOOLEAN |
| Date | DATE |
| Date and time | TIMESTAMP |
| Short text | TEXT |
| Long text | TEXT |
| Binary data | BYTEA |
Working from a .json file
A .json file can be almost any shape, and only a few of those shapes are a table. What the reader accepts, and what it does with the rest, is the thing worth knowing before you upload one.
- →A wrapper is unwrapped only when the object has exactly one key and that key holds a list of objects. {"meta": {...}, "data": [...]} has two keys, so it is read as a single row instead.
- →An array of strings, or an array of arrays, is refused with "Expected a JSON array of objects" - there are no column names in it to build a table from.
- →Columns are the union of the keys seen in the first 10,000 records, in the order they first appear. A key that shows up only after that is not part of the table.
Loading into an application's database
PGSQL is the name PostgreSQL wears inside application code: PHP's pgsql extension, Laravel's pgsql connection driver, the pdo_pgsql DSN prefix. If that is where you met the name, the database you are loading into probably belongs to a framework, which changes what to watch for.
- →The script creates its own tables. Point it at a schema your migrations own and the next migration run and this file will disagree about who defines the table - load into an empty schema, or a database of its own, and point the application at that.
- →Because every identifier is double-quoted, the case the source used is the case that gets stored. A column that arrives as "CustomerID" has to be quoted in your queries too: an unquoted CustomerID folds to customerid and is not found.
- →No FOREIGN KEY, index or view statement is generated at all, so a framework that introspects the database finds unrelated tables. Declare the relations in your models, or add them with ALTER TABLE once the rows are in.
Reading JSON
- →JSON types are trusted: 1 and "1" stay different things.
- →Numbers with a decimal point are read as exact decimals rather than floats.
- →Both an array of objects and newline-delimited JSON work, and a wrapped array like {"data": [...]} is unwrapped automatically.
- →Nested objects are kept as JSON rather than flattened into invented column names.
Writing PGSQL
- →Backslashes are left alone, because PostgreSQL treats them as ordinary characters — doubling them would corrupt every Windows path.
- →Auto-increment columns become GENERATED BY DEFAULT AS IDENTITY.
- →Binary data is written as bytea, and identifiers respect the 63-character limit.
What you get
A ZIP containing dump.sql, plus a README with the exact command to load it. If anything about your data needed a judgement call, a _warnings.txt explains it.
Load this dump into PostgreSQL: psql -U USER -d DATABASE -f dump.sql Create the database first if it does not exist: createdb -U USER DATABASE
Questions
- Is converting JSON to PGSQL free?
- Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.
- Will my JSON data keep its types in PGSQL?
- Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real PGSQL types rather than everything becoming text. The mapping table above shows exactly what you get.
- Do you store my file?
- No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.