mdbr 0.4.0

Breaking changes

• Binary and OLE fields are now returned as list columns of raw vectors instead of character strings (#18).

• Empty text values are now returned as "" instead of NA. Only NULL values become NA (#18).

• mdb_example() now returns the bundled Northwind database (nwind.mdb). The nycflights13 example file has been removed (#18).

New features

• New mdb_stream_table() opens a table as a DBI result that can be read in batches with DBI::dbFetch(), keeping memory use bounded for large tables. dbReadTable() and read_mdb() now read through the same cursor. SQL queries sent with dbSendQuery() are still read in full (#18, @meztez).

Bug fixes

• dbFetch() now advances through dbSendQuery() results across successive calls, and dbHasCompleted() reports completion correctly (#18).

• dbFetch() accepts n = 0 and returns a zero-row data frame with the correct column types. dbIsValid() is now FALSE after dbClearResult() (#18).

mdbr 0.3.2

• Fix const qualifier warning in fakeglib.c flagged by GCC 16 on Fedora (#17).

mdbr 0.3.1

mdbr 0.3.0

• The mdbtools C library is now compiled and bundled with the package. No external mdbtools installation is required on any platform (#3).

• A full read-only DBI backend is now available via mdb() (#6):

  con <- DBI::dbConnect(mdb(), dbname = "path/to/file.mdb")
  DBI::dbListTables(con)
  DBI::dbGetQuery(con, "SELECT * FROM [Orders] LIMIT 10;")
  DBI::dbDisconnect(con)

• New helper functions: mdb_sql(), mdb_queries(), mdb_count(), mdb_json(), mdb_export(), mdb_ver(), mdb_array(), mdb_header(), mdb_hexdump(), and mdb_prop().

• mdb_schema() gains a mode argument for DDL output in multiple SQL dialects in addition to the existing readr col-spec mode.

• read_mdb() now reads tables via the bundled C library and returns a tibble. The col_types and ... arguments are deprecated with a lifecycle warning.

• readr is no longer a hard dependency. If you use read_mdb() and rely on readr being available, add it explicitly to your own dependencies.

• Thanks to Bruno Tremblay for contributing the bundled mdbtools source, the DBI backend, and the expanded helper functions (#9).

mdbr 0.2.1

• Update maintainer email, website URL, and GitHub URL.

mdbr 0.2.0

• Functions now quote their input files with shQuote(). (#7)
• export_mdb() now mirrors readr::format_csv() with arguments, etc.
• Remove all formatting arguments for read_mdb() (with smart hidden defaults).
• Add more schema types with readr equivalents.
• Write schema to a matrix in-memory rather than a temporary file.
• Always read data from a temporary file instead of stdout option.
• Add better checking if mdbtools is installed.

mdbr 0.1.1

• read_mdb() now has stdout() which can take TRUE or a file path.
• Examples and tests don’t run on CRAN.

mdbr 0.1.0

• Added a NEWS.md file to track changes to the package.
• Cover the most basic functions from mdbtools:
  • List tables in database
  • Export table as delimited file
  • Read delimited file as dataframe
  • Convert simple schema to readr spec