Is converting DDB to MySQL 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 DDB data keep its types in MySQL?

Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real MySQL 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.

Convert DDB to MySQL

Upload a .duckdb or .ddb file and get back a MySQL SQL script you can load straight into your database. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.

1Upload your file

Click to upload or drag and drop

CSV, Excel, SQLite, SQL, DBF (max 10 MB)

2Choose target format

How your data is typed in MySQL

Generated from the converter's own MySQL type mapping — this is what it actually emits, not an example.

Your data	MySQL type
Whole number	BIGINT
Decimal (money)	DECIMAL(10,2)
Floating point	DOUBLE
True / false	TINYINT(1)
Date	DATE
Date and time	DATETIME
Short text	VARCHAR(255)
Long text	LONGTEXT
Binary data	LONGBLOB

Working from a .ddb file

.ddb is the short form of the DuckDB extension, and DuckDB itself does not care what you call a database file. The uploader does: it routes on the extension alone, so the name you saved under decides which reader ever sees the file.

→.ddb and .duckdb both reach the DuckDB reader and are read identically. Nothing inside the file records which of the two you chose - the storage version is in the header, the name is not.
→One file is this format's whole promise, so make sure it really is one file before you send it: closing the DuckDB CLI cleanly, or running CHECKPOINT first, folds the write-ahead log back into the database itself.
→A file with no extension at all, which DuckDB is perfectly happy to create, is not recognised as anything and is refused before it is read.

Loading the dump into MySQL

The download is a plain SQL script, so nothing in it depends on how you connect: the same file goes in through the command-line client, through a GUI import dialog or through phpMyAdmin. What is worth reading first is the handful of statements it runs before it creates anything.

→Before the first CREATE TABLE the script issues SET NAMES utf8mb4, so the session decodes the file as UTF-8 whatever the client's own default character set is. The file itself carries no marker saying so.
→The line after it turns FOREIGN_KEY_CHECKS off. That is there for the schema you are loading into, not for the script: it lets rows arrive in whatever order the tables came out of the source without a constraint that already exists rejecting them.
→A true/false column is declared TINYINT(1) and its values are written as 1 and 0. MySQL's own BOOLEAN keyword expands to exactly that, so a client that does not special-case the width shows you a number rather than a boolean.

Reading DDB

→Types, primary keys and NOT NULL constraints are read from the database.
→The file is opened read-only, so your upload is never modified or upgraded in place.

Writing MySQL

→Tables are created as InnoDB with utf8mb4, so emoji and CJK text survive the load.
→Backslashes are escaped, because MySQL treats them as escape characters by default.
→Text columns of unknown length become TEXT rather than a guessed VARCHAR that could truncate your data.
→Inserts are batched, and identifiers are capped at MySQL’s 64-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 MySQL or MariaDB:

  mysql -u USER -p DATABASE < dump.sql

Create the database first if it does not exist:

  mysql -u USER -p -e "CREATE DATABASE DATABASE CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;"

Questions

Is converting DDB to MySQL 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 DDB data keep its types in MySQL?: Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real MySQL 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.