Package "swiplite"

Title:	Prolog bindings for SQLite3
Rating:	Not rated. Create the first rating!
Latest version:	1.1
SHA1 sum:	398dea3a572f0bb0ef1b0a92f06db3854afd9fe6
Author:	Boris Vassilev <boris.vassilev@gmail.com>

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Details by download location

Version	SHA1	#Downloads	URL
1.1	398dea3a572f0bb0ef1b0a92f06db3854afd9fe6	3	https://github.com/borisvassilev/swiplite/archive/V1.1.zip
0.3	1ea2a5f73cdecab972c1ad811763db430a7ac202	21	https://github.com/borisvassilev/swiplite/archive/V0.3.zip
0.2	8be0cc945cf9cb4bef7c82f694e3d0e1f3d7ede1	3	https://github.com/borisvassilev/swiplite/archive/0.2.zip
0.1.1	b151e55053849d23a1eb2cb6ac28fca155f0076c	3	https://github.com/borisvassilev/swiplite/archive/0.1.1.zip
0.1	01eee77379899032f179f740c7548651a1b93408	3	https://github.com/borisvassilev/swiplite/archive/0.1.zip

SQLite for SWI-Prolog

The purpose of swiplite is to enable using sqlite3 databases comfortably from SWI-Prolog, without sacrificing efficiency.

The prolog/sqlite.pl provides low-level access to the connection and statement objects.

In addition to this document, there is a discussion on the SQLITEDOC.md in comparison to other relational databases. There is DEVELOPMENT.md summarizing information about the development process of the library.

Requirements

This has been developed and tested on Linux and Mac OS.

You might already have a decently recent version of SQLite installed; you can also install it using the package manager for your OS. On MacOS, it is strongly recommended to install SQLite from Homebrew and make sure this library is linked against it. The default SQLite that comes with MacOS is somewhat out of date and seems to be compiled with questionable flags, probably for backwards compatibility.

Finally, since this package contains C code, you need CMake and a C compiler.

Installation

The pack has been already published. To get the latest release:

$ swipl pack install swiplite

... or from the top level:

?- pack_install(swiplite).

Installing from source

The code is available in the public GitHub repository https://github.com/borisvassilev/swiplite. To install from the source, clone the repo and install from the pack directory:

$ git clone https://github.com/borisvassilev/swiplite.git
$ cd swiplite
$ swipl pack install .

Alternatively, create an archive and install it locally:

$ git archive --output=swiplite-<version>.tgz <tree-ish>
$ swipl pack install swiplite-<version>.tgz

Embedding the SQLite source

If you prefer to use the SQLite source provided on SQLite's download page, you can do it by first checking out its own branch, sqlite3-amalgamation. Once you add the two files you will find in the amalgamation, sqlite3.c and sqlite3.h, in the `c/` subdirectory, you should see:

$ git status
On branch sqlite3-amalgamation
Your branch is up to date with 'origin/sqlite3-amalgamation'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        c/sqlite3.c
        c/sqlite3.h

nothing added to commit but untracked files present (use "git add" to track)

You can now build and install the library from the local repo as described above.

Smoke test

To check that you have installed the add-on correctly:

?- use_module(library(sqlite)).
true.

?- sqlite_version(V).
V = '3.53.0'.

The predicate sqlite_version/1 opens an in-memory SQLite database and queries `Select sqlite_version()`.

Background

There are many alternatives to using the swiplite pack. Here is a list of questions I have asked myself before I started working on it (and repeatedly ever since), along with attempts at answers.

Why SQL?

There is no good reason to use SQL; other than, it is the standard interface to relational databases.

Why a relational database?

... especially since you are using Prolog already?

Relational databases come with features that are not available out of the box on SWI-Prolog:

• Foreign key, unique, and check constraints;
• Disk persistency.

Why SQLite?

SQLite provides a full-featured relational database almost for free, in terms of setup and resources needed.

Why not ODBC?

SWI-Prolog provides a full-featured ODBC interface. However, specifically in the case of SQLite, it requires a clumsy setup with extra dependencies and no obvious benefit.

Why not proSQLite?

proSQLite is a mature SWI-Prolog interface to SQLite also available as a pack. Unfortunately, I was not able to figure out how to use it to create prepared statements with SQL parameters and bind values to them.

Why do you need prepared statements?

It is very likely that prepared statements are not that important. On the other hand, there is the cautionary tale of Little Bobby Tables.

I have described one bug and feature in SQLITEDOC.md, in "Using a literal in an SQL statement": a Prolog integer that does not fit in an 8-byte signed integer will be silently converted to an SQLite REAL, and the original value will be irreversibly lost. In contrast, if you use a prepared statement as provided by this library, swiplite, and you attempt to bind an integer that does not fit, you will get a run-time error.

Further work

This library has been used by me for about a year at this point of time (2026-04-25) and it has served me well, for the very limited purposes I have had. A couple of features I would sometimes wish I would have had:

• Transparent support for all data types in SWI-Prolog. As it is right now, you need to stringify large integers, rational numbers, compound terms, and so on, before inserting them in your SQLite database, and re-create them when you retrieve them.
• An efficient transparent support for compound terms not based on stringifying.
• A clean high-level interface. The main reason I have not provided it publicly is that I am not sure what might be generally useful to others and the work involved is too boring.

In addition, the CMakeLists.txt currently provided in this library happens to work for the two machines I have in daily use. In the unlikely case that someone else wants to use this library they might be able to propose improvements.

Contents of pack "swiplite"

Pack contains 8 files holding a total of 102K bytes.