Convert FoxPro to SQLite3

Working from a FoxPro table

FoxPro extended the dBase file layout with types dBase never had, and gave its memo files a different format and a different extension. Both of those differences change what comes out the other side, and both are read from the file.

• →The FoxPro-only field types are read as themselves: Currency (Y) becomes an exact decimal rather than a float, Integer (I) a 64-bit integer, DateTime (T) a timestamp, Double (B) a floating-point number.
• →Memo text is expected in a .fpt, chosen from the Visual FoxPro and FoxPro 2.x version bytes 0x30, 0x31, 0x32, 0xF5 and 0xFB, rather than in the dBase .dbt.
• →Only the .dbf itself is read. A table bound to a Visual FoxPro database container keeps its long field names and relations in the .dbc, so columns arrive under the short names in the table header.

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 FoxPro

• →Numeric fields with decimals are read as exact decimals, not floats, so currency does not drift.
• →Character field widths are read from the header and carried into the target.
• →The code page declared in the file header is used, so Cyrillic, Western European and other legacy DOS encodings decode correctly instead of turning into mojibake. 157 code pages are recognised.
• →Files written by dBase III or Clipper declare no code page at all — the header byte for it did not exist yet. For those, the most plausible encoding is chosen by inspecting the text, and the conversion tells you it had to guess. The API takes a sourceEncoding parameter (e.g. cp866) to force it instead of guessing, though the widget above does not have a control for it yet.
• →Memo columns keep their text in a separate .dbt or .fpt file. If the .dbf declares one and it was not uploaded, the conversion stops and tells you which file to add, rather than handing you a table whose long text is silently blank.

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.

Convert FoxPro to something else

• MySQL
• PostgreSQL
• Oracle
• SQL Server
• DuckDB
• CSV
• Excel

Convert something else to SQLite3

• CSV
• Excel
• SQL dump
• JSON
• XML
• Parquet
• DuckDB
• MS Access
• PostgreSQL backup