Please add to readme info below.
(1.) Macos and linux HOWTO.
To create sqlite3.mex on macosx or linux.

• Macos brew install octave && git clone https://github.com/rmartinjak/mex-sqlite3.git
• Linux. Get mkoctfile. Debian/Ubuntu: apt-get install liboctave-dev

mkoctfile --mex -lsqlite3 -loctave -o sqlite3.mex sqlite3.c structlist.c . && cp sqlite3.mex ~/octave/ && octave
GNU Octave, version 4.4.1
octave:1> sqlite3
error: sqlite3: usage: sqlite3(file, query[, params]

I tried putting sqlite3.mex in octave path, but only seems to find it if running from dir where it is. That is I have same problem in octave as does @chappjc in matlab per their comment at https://stackoverflow.com/questions/26189163/mex-compiled-function-not-recognized-by-matlab

Thanks, I its weird, I had to explicitly go to the directory of the mex file and only then did the function become available. Adding its directory via addpath(genpath('the/path')) did not work for some reason

I copied sqlite3.mex to ~/Documents/MATLAB/ but matlab still says Undefined function or variable 'sqlite3' so Matlab does not recognize .mex. Maybe sqlite3.mex is really is an .oct file, as mkoctfile creates identical files with and without --mex. If I rename it sqlite3.mexmaci64 it crashes matlab.

(2.) Windows and Linux binaries.
At matlab FEX site for sqlite3 you can download a zip with compiled_mex folder that has one linux binary, and all the rest are windows binaries:

862208 Apr 11 2018 sqlite3_matlab.exe 
966706 Mar 3 2017 sqlite3_matlab.mexa64 
741888 Mar 3 2017 sqlite3_matlab.mexw32 
962560 Mar 3 2017 sqlite3_matlab.mexw64 
29032 May 13 2018 sqlite3_octave_lnx_i686.mex 
145052 May 13 2018 sqlite3_octave_win_64.mex 
114247 May 13 2018 sqlite3_octave_win_i686.mex