Installation and Using SQLite3 extensions ↑

This document will help you install the sqlite3 ruby gem. It also contains instructions on loading database extensions and building against drop-in replacements for sqlite3.

Installation ↑

Native Gems (recommended) ↑

In v2.0.0 and later, native (precompiled) gems are available for recent Ruby versions on these platforms:

⚠ Musl linux users should update to Bundler >= 2.5.6 to avoid github.com/rubygems/rubygems/issues/7432

If you are using one of these Ruby versions on one of these platforms, the native gem is the recommended way to install sqlite3-ruby.

For example, on a linux system running Ruby 3.1:

$ ruby -v
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]

$ time gem install sqlite3
Fetching sqlite3-1.5.0-x86_64-linux.gem
Successfully installed sqlite3-1.5.0-x86_64-linux
1 gem installed

real    0m4.274s
user    0m0.734s
sys     0m0.165s

Avoiding the precompiled native gem ↑

The maintainers strongly urge you to use a native gem if at all possible. It will be a better experience for you and allow us to focus our efforts on improving functionality rather than diagnosing installation issues.

If you’re on a platform that supports a native gem but you want to avoid using it in your project, do one of the following:

Compiling the source gem ↑

If you are on a platform or version of Ruby that is not covered by the Native Gems, then the vanilla “ruby platform” (non-native) gem will be installed by the gem install or bundle commands.

Packaged libsqlite3 ↑

By default, as of v1.5.0 of this library, the latest available version of libsqlite3 is packaged with the gem and will be compiled and used automatically. This takes a bit longer than the native gem, but will provide a modern, well-supported version of libsqlite3.

⚠ A prerequisite to build the gem with the packaged sqlite3 is that you must have pkgconf installed.

For example, on a linux system running Ruby 2.5:

$ ruby -v
ruby 2.5.9p229 (2021-04-05 revision 67939) [x86_64-linux]

$ time gem install sqlite3
Building native extensions. This could take a while...
Successfully installed sqlite3-1.5.0
1 gem installed

real    0m20.620s
user    0m23.361s
sys     0m5.839s
Controlling compilation flags for sqlite ↑

Upstream sqlite allows for the setting of some parameters at compile time. If you’re an expert and would like to set these, you may do so at gem install time in two different ways …

If you’re installing the gem using gem install then you can pass in these compile-time flags like this:

gem install sqlite3 --platform=ruby -- \
  --with-sqlite-cflags="-DSQLITE_DEFAULT_CACHE_SIZE=9999 -DSQLITE_DEFAULT_PAGE_SIZE=4444"

or the equivalent:

CFLAGS="-DSQLITE_DEFAULT_CACHE_SIZE=9999 -DSQLITE_DEFAULT_PAGE_SIZE=4444" \
  gem install sqlite3 --platform=ruby

If you’re installing the gem using bundler then you should first pin the gem to the “ruby” platform gem, so that you are compiling from source:

# Gemfile
gem "sqlite3", force_ruby_platform: true # requires bundler >= 2.3.18

and then set up a bundler config parameter for build.sqlite3:

bundle config set build.sqlite3 \
  "--with-sqlite-cflags='-DSQLITE_DEFAULT_CACHE_SIZE=9999 -DSQLITE_DEFAULT_PAGE_SIZE=4444'"

NOTE the use of single quotes within the double-quoted string to ensure the space between compiler flags is interpreted correctly. The contents of your .bundle/config file should look like:

---
BUNDLE_BUILD__SQLITE3: "--with-sqlite-cflags='-DSQLITE_DEFAULT_CACHE_SIZE=9999 -DSQLITE_DEFAULT_PAGE_SIZE=4444'"

System libsqlite3 ↑

If you would prefer to build the sqlite3-ruby gem against your system libsqlite3, which requires that you install libsqlite3 and its development files yourself, you may do so by using the --enable-system-libraries flag at gem install time.

PLEASE NOTE:

For example, on a linux system running Ruby 2.5:

$ time gem install sqlite3 -- --enable-system-libraries
Building native extensions with: '--enable-system-libraries'
This could take a while...
Successfully installed sqlite3-1.5.0
1 gem installed

real    0m4.234s
user    0m3.809s
sys     0m0.912s

If you’re using bundler, you can opt into system libraries like this:

bundle config build.sqlite3 --enable-system-libraries

If you have sqlite3 installed in a non-standard location, you may need to specify the location of the include and lib files by using --with-sqlite-include and --with-sqlite-lib options (or a --with-sqlite-dir option, see MakeMakefile#dir_config). If you have pkg-config installed and configured properly, this may not be necessary.

gem install sqlite3 -- \
  --enable-system-libraries \
  --with-sqlite3-include=/opt/local/include \
  --with-sqlite3-lib=/opt/local/lib

System libsqlcipher ↑

If you’d like to link against a system-installed libsqlcipher, you may do so by using the --with-sqlcipher flag:

$ time gem install sqlite3 -- --with-sqlcipher
Building native extensions with: '--with-sqlcipher'
This could take a while...
Successfully installed sqlite3-1.5.0
1 gem installed

real    0m4.772s
user    0m3.906s
sys     0m0.896s

If you have sqlcipher installed in a non-standard location, you may need to specify the location of the include and lib files by using --with-sqlite-include and --with-sqlite-lib options (or a --with-sqlite-dir option, see MakeMakefile#dir_config). If you have pkg-config installed and configured properly, this may not be necessary.

Using SQLite3 extensions ↑

How do I load a sqlite extension? ↑

Some add-ons are available to sqlite as “extensions”. The instructions that upstream sqlite provides at www.sqlite.org/loadext.html are the canonical source of advice, but here’s a brief example showing how you can do this with the sqlite3 ruby gem.

In this example, I’ll be loading the “spellfix” extension:

# download spellfix.c from somewherehttp://www.sqlite.org/src/finfo?name=ext/misc/spellfix.c
$ wget https://raw.githubusercontent.com/sqlite/sqlite/master/ext/misc/spellfix.c
spellfix.c                     100%[=================================================>] 100.89K  --.-KB/s    in 0.09s

# follow instructions at https://www.sqlite.org/loadext.html
# (you will need sqlite3 development packages for this)
$ gcc -g -fPIC -shared spellfix.c -o spellfix.o

$ ls -lt
total 192
-rwxrwxr-x 1 flavorjones flavorjones  87984 2023-05-24 10:44 spellfix.o
-rw-rw-r-- 1 flavorjones flavorjones 103310 2023-05-24 10:43 spellfix.c

Then, in your application, use that spellfix.o file like this:

require "sqlite3"

db = SQLite3::Database.new(':memory:')
db.enable_load_extension(true)
db.load_extension("/path/to/sqlite/spellfix.o")
db.execute("CREATE VIRTUAL TABLE demo USING spellfix1;")

How do I use my own sqlite3 shared library? ↑

Some folks have strong opinions about what features they want compiled into sqlite3; or may be using a package like SQLite Encryption Extension (“SEE”). This section will explain how to get your Ruby application to load that specific shared library.

If you’ve installed your alternative as an autotools-style installation, the directory structure will look like this:

/opt/sqlite3
├── bin
│   └── sqlite3
├── include
│   ├── sqlite3.h
│   └── sqlite3ext.h
├── lib
│   ├── libsqlite3.a
│   ├── libsqlite3.la
│   ├── libsqlite3.so -> libsqlite3.so.0.8.6
│   ├── libsqlite3.so.0 -> libsqlite3.so.0.8.6
│   ├── libsqlite3.so.0.8.6
│   └── pkgconfig
│       └── sqlite3.pc
└── share
    └── man
        └── man1
            └── sqlite3.1

You can build this gem against that library like this:

gem install sqlite3 --platform=ruby -- \
  --enable-system-libraries \
  --with-opt-dir=/opt/sqlite

Explanation:

Alternatively, if you’ve simply downloaded an “amalgamation” and so your compiled library and header files are in arbitrary locations, try this more detailed command:

gem install sqlite3 --platform=ruby -- \
  --enable-system-libraries \
  --with-opt-include=/path/to/include \
  --with-opt-lib=/path/to/lib