Convert MS Access to PostgreSQL
Upload a .mdb or .accdb or .mde file and get back a PostgreSQL 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 PostgreSQL
Generated from the converter's own PostgreSQL type mapping — this is what it actually emits, not an example.
| Your data | PostgreSQL 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 an Access database
An Access file is an application as much as a database: tables, but also queries, forms, reports, macros and VBA modules. Only one of those is data, and only that one is something a conversion can carry anywhere else.
- →The tables convert. Saved queries, forms, reports, macros and modules are not data and do not appear in the output - re-create a query as a view in the target if you need it.
- →Access types map to fixed shapes: Currency to DECIMAL(19,4), matching Access's own four fixed decimal places, Decimal to DECIMAL(18,6), Long Integer to a 32-bit integer, Byte and Integer to 16-bit, Memo and Hyperlink to text, OLE and Binary to a blob.
- →If the file cannot be opened at all - a database password, or real damage - the conversion stops with the underlying tool's own error instead of handing you a partial result.
What the PostgreSQL script contains
The conversion produces one dump.sql with a README beside it, zipped. It is a script you can open, grep and edit before you run it rather than an archive a tool has to unpack, and it is deliberately sparing in what it declares.
- →Every string column is declared TEXT, whatever length the source declared for it. PostgreSQL stores a short value in a TEXT column exactly as cheaply as in a VARCHAR, and an unbounded column cannot reject a row on load for being a few characters too long.
- →Identifiers are all double-quoted, and even so a name on PostgreSQL's reserved list is given a trailing underscore: a column called user arrives as user_, order as order_, limit as limit_.
- →A decimal column whose source declared no scale is given six decimal places rather than none, keeping whatever precision it did declare: NUMERIC(10,6) from a source that said 10, and NUMERIC(18,6) from one that declared neither. A scale of zero would have the server round 19.99 to 20 as it loaded.
Reading MS Access
- →Dates are exported in ISO form, avoiding the ambiguous 12/02/21 that Access tools produce by default.
- →NULL and the empty string stay distinct.
- →Access can hold dates outside the range it can represent. Those become NULL and the conversion tells you, rather than dropping them silently.
- →Requires mdbtools on the server; if it is unavailable you get a clear error rather than a partial conversion.
Writing PostgreSQL
- →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 MS Access to PostgreSQL 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 MS Access data keep its types in PostgreSQL?
- Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real PostgreSQL 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.