Convert DDB to SQLite3
Upload a .duckdb or .ddb file and get back a SQLite3 file. 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 SQLite3
Generated from the converter's own SQLite3 type mapping — this is what it actually emits, not an example.
| Your data | SQLite3 type |
|---|---|
| Whole number | BIGINT |
| Decimal (money) | NUMERIC(10,2) |
| Floating point | REAL |
| True / false | BOOLEAN |
| Date | DATE |
| Date and time | TIMESTAMP |
| Short text | TEXT |
| Long text | TEXT |
| Binary data | BLOB |
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.
The .sqlite3 name and what carries over
The 3 in sqlite3 is the file format version and the name of the command-line tool, not a property of your conversion. One database file arrives, and the two things worth knowing about it are what it is called and what it leaves behind.
- →The file inside the zip is always database.sqlite, whichever spelling brought you to this page. Rename it to database.sqlite3, or to whatever a framework expects, once you have it - the header is what identifies it, never the extension.
- →An auto-increment column arrives holding all of its values and nothing that assigns new ones. No AUTOINCREMENT keyword is written, and the column is declared BIGINT rather than exactly INTEGER, so it is not an alias for the rowid either: rows you insert later have to supply their own key.
- →Only the rows are transactional. The very first CREATE TABLE runs in autocommit, and everything after it - that table's rows, and every later table - sits in one transaction that commits after the last row. A conversion that fails partway therefore leaves a file holding an empty shell of the first table and nothing else. You never receive that file: the zip is only assembled once the writer has returned.
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 SQLite3
- →Columns get real declared types rather than everything being TEXT.
- →Primary keys and NOT NULL constraints are preserved.
- →A money column is declared NUMERIC(10,2), but that declaration does not stop SQLite’s own numeric affinity from converting the inserted value into a float once it lands, so 19.99 can come back with a rounding tail. Pick the DuckDB target instead when the exact decimal has to survive.
What you get
A ZIP containing database.sqlite. If anything about your data needed a judgement call, a _warnings.txt explains it.
Questions
- Is converting DDB to SQLite3 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 SQLite3?
- Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real SQLite3 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.