How to install OCAMLODBC as findlib package

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A stub library (and a bit more) for the ODBC[1] interface is provided by Maxence Guesdon and can be downloaded here. Unfortunately, the distributed makefile does neither support dynamic libraries nor the installation as findlib package. The following text shows how to do that. It applies to version 2.5 of ocamlodbc, but only to the unixodbc option. (For the other supported types of DB connections the following is probably not fully incorrect, but simply not exactly matching.)

First, configure and build as described in the README:

./configure
make unixodbc

Now we will improve the result of the build process. First, we recompile ocaml_odbc_c.c for usage in a shared library:

ocamlc -c -ccopt -pthread -ccopt '-D unixODBC' -I `ocamlc -where`/caml \
    -verbose ocaml_odbc_c.c

Note that I have copied the options "-pthread" and "-D unixODBC" from the original build process. Now create the libraries:

ocamlmklib -verbose -o ocamlodbc ocaml_odbc.cmo ocamlodbc.cmo \
   ocaml_odbc.cmx ocamlodbc.cmx ocaml_odbc_c.o -lodbc

This should generate dllocamlodbc.so, libocamlodbc.a, ocamlodbc.cma, ocamlodbc.cmxa, and ocamlodbc.a. Previous versions of these files are overwritten. Copy everything to the directory unixodbc:

cp dllocamlodbc.so libocamlodbc.a ocamlodbc.mli ocamlodbc.cma /
   ocamlodbc.cmxa ocamlodbc.a ocamlodbc.cmi ocaml_odbc.cmi unixodbc/

Go into this directory, create a META file, and install the package:

cd unixodbc
cat <<EOF >META
> version = "2.5"
> description = "Database interface with ODBC"
> archive(byte) = "ocamlodbc.cma"
> archive(native) = "ocamlodbc.cmxa"
> EOF
ocamlfind install ocamlodbc *

Now test if everything has worked:

$ ocaml
        Objective Caml version 3.06

# #use "topfind";;
Findlib has been successfully loaded. Additional directives:
  #require "package";;      to load a package
  #list;;                   to list the available packages
  #camlp4o;;                to load camlp4 (standard syntax)
  #camlp4r;;                to load camlp4 (revised syntax)
  Topfind.reset();;         to force that packages will be reloaded

- : unit = ()
# #require "ocamlodbc";;
Loading /opt/ocaml-3.06/site-lib/ocamlodbc/ocamlodbc.cma
# module M = Ocamlodbc;;
module M :
  (omitted)
#

If you get errors, something went wrong.

[1]: Open Database Connectivity

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