docs: update caching docs

Now that emacsql handles choosing an appropriate backend/connector, we
do not need to provide these instructions.  If there are issues, emacsql
has good error messages that tell the user what they need to do to get
things working.

In general:
  - If the user is on Emacs >= 29, emacsql will use the built-in sqlite
    functionality that comes with Emacs.
  - If the user is on Emacs < 29, emacsql will use a module-based
    connector that requires the user to have certain libraries available
    on their machine.  emacsql will tell the user what is needed if they
    do not have it already.

Ref: #2486
Close: #2502
Close: #2415

README.md

@@ -153,9 +153,8 @@ dependencies. These include:
 - dash
 - f
 - s
-- org (9.4 is the minimal required version!)
+- org (9.6 is the minimum required version!)
 - emacsql
-- emacsql-sqlite
 - magit-section
 - filenotify-recursive
 

doc/org-roam.org

@@ -224,7 +224,6 @@ dependencies that it requires. These include:
 - s
 - org
 - emacsql
-- emacsql-sqlite
 - magit-section
 
 You can install this manually as well, or get the latest version from MELPA. You
@@ -423,43 +422,8 @@ can set ~org-roam-node-display-template~ as such:
 
 * Customizing Node Caching
 ** How to cache
-
+Org-roam uses a SQLite database to perform caching.  This integration is
-Org-roam uses a sqlite database to perform caching, but there are multiple Emacs
+managed by the [[https://github.com/magit/emacsql][emacsql]] library.  It should "just work".
-libraries that can be used. The default used by Org-roam is
-[[https://github.com/magit/emacsql/blob/main/emacsql-sqlite-builtin.el][~emacs-sqlite-builtin~]].  Below the pros and cons of each package is used:
-
-[[https://melpa.org/#/emacsql-sqlite-builtin][**emacsql-sqlite-builtin**]]
-
-~emacsql-sqlite-builtin~ uses the in-built SQLite support for Emacs 29 and
-later. This is the default option if you are using a version of Emacs that
-supports it.
-
-#+begin_src emacs-lisp
-  (setq org-roam-database-connector 'sqlite-builtin)
-#+end_src
-
-[[https://github.com/cireu/emacsql-sqlite3][**emacs-sqlite3**]]
-
-~emacs-sqlite3~ uses the official sqlite3 binary that can be obtained from your
-system's package manager. This is useful if you have issues producing the
-~sqlite3~ binary required by the other packages. However, it is not recommended
-because it has some compatibility issues with Emacs, but should work for most
-regular cases. See [[https://nullprogram.com/blog/2014/02/06/][Chris Wellon's blog post]] for more information.
-
-To use ~emacsql-sqlite3~, ensure that the package is installed, and set:
-
-#+begin_src emacs-lisp
-  (setq org-roam-database-connector 'sqlite3)
-#+end_src
-
-[[https://melpa.org/#/emacsql-sqlite-module][**emacssql-sqlite-module**]] (previously emacsql-libsqlite3)
-
-~emacs-sqlite-module~ is a relatively young package which uses an Emacs module that
-exposes parts of the SQLite C API to Emacs Lisp.
-
-#+begin_src emacs-lisp
-  (setq org-roam-database-connector 'sqlite-module)
-#+end_src
 
 ** What to cache
 
@@ -481,7 +445,7 @@ property to a non-nil value. For example:
 One can also set ~org-roam-db-node-include-function~. For example, to exclude
 all headlines with the ~ATTACH~ tag from the Org-roam database, one can set:
 
-#+begin_src org
+#+begin_src emacs-lisp
 (setq org-roam-db-node-include-function
       (lambda ()
         (not (member "ATTACH" (org-get-tags)))))

doc/org-roam.texi

@@ -441,8 +441,6 @@ org
 @item
 emacsql
 @item
-emacsql-sqlite
-@item
 magit-section
 @end itemize
 
@@ -685,42 +683,8 @@ can set @code{org-roam-node-display-template} as such:
 @node How to cache
 @section How to cache
 
-Org-roam uses a sqlite database to perform caching, but there are multiple Emacs
+Org-roam uses a SQLite database to perform caching.  This integration is
-libraries that can be used. The default used by Org-roam is
+managed by the @uref{https://github.com/magit/emacsql, emacsql} library.  It should ``just work''.
-@uref{https://github.com/magit/emacsql/blob/main/emacsql-sqlite-builtin.el, @code{emacs-sqlite-builtin}}.  Below the pros and cons of each package is used:
-
-@uref{https://melpa.org/#/emacsql-sqlite-builtin, @strong{@strong{emacsql-sqlite-builtin}}}
-
-@code{emacsql-sqlite-builtin} uses the in-built SQLite support for Emacs 29 and
-later. This is the default option if you are using a version of Emacs that
-supports it.
-
-@lisp
-(setq org-roam-database-connector 'sqlite-builtin)
-@end lisp
-
-@uref{https://github.com/cireu/emacsql-sqlite3, @strong{@strong{emacs-sqlite3}}}
-
-@code{emacs-sqlite3} uses the official sqlite3 binary that can be obtained from your
-system's package manager. This is useful if you have issues producing the
-@code{sqlite3} binary required by the other packages. However, it is not recommended
-because it has some compatibility issues with Emacs, but should work for most
-regular cases. See @uref{https://nullprogram.com/blog/2014/02/06/, Chris Wellon's blog post} for more information.
-
-To use @code{emacsql-sqlite3}, ensure that the package is installed, and set:
-
-@lisp
-(setq org-roam-database-connector 'sqlite3)
-@end lisp
-
-@uref{https://melpa.org/#/emacsql-sqlite-module, @strong{@strong{emacssql-sqlite-module}}} (previously emacsql-libsqlite3)
-
-@code{emacs-sqlite-module} is a relatively young package which uses an Emacs module that
-exposes parts of the SQLite C API to Emacs Lisp.
-
-@lisp
-(setq org-roam-database-connector 'sqlite-module)
-@end lisp
 
 @node What to cache
 @section What to cache
@@ -743,11 +707,11 @@ property to a non-nil value. For example:
 One can also set @code{org-roam-db-node-include-function}. For example, to exclude
 all headlines with the @code{ATTACH} tag from the Org-roam database, one can set:
 
-@example
+@lisp
 (setq org-roam-db-node-include-function
       (lambda ()
         (not (member "ATTACH" (org-get-tags)))))
-@end example
+@end lisp
 
 Org-roam relied on the obtained Org AST for the buffer to parse links. However,
 links appearing in some places (e.g. within property drawers) are not considered

org-roam.el

@@ -80,7 +80,9 @@
 (require 'magit-section)
 
 (require 'emacsql)
-;; emacsql-sqlite provides an interface to a chosen emacsql SQLite backend (e.g. emacs-sqlite-builtin)
+;; REVIEW: is this require needed?
+;; emacsql-sqlite provides a common interface to an emacsql SQLite backend (e.g. emacs-sqlite-builtin)
+;; not to be confused with a backend itself named emacsql-sqlite that existed in emacsql < 4.0.
 (require 'emacsql-sqlite)
 
 (require 'org)