a_hello.erl

% ------------------------------------------------------------------------
% Hello World: Minimal sample of Emysql
% H. Diedrich <hd2010@eonblast.com> - Eonblast http://www.eonblast.com
% 11 Jun 2010
% ------------------------------------------------------------------------
% 
% This sample inserts 'Hello World!' into a mysql table and reads it back.
%
% If you have trouble, try the simpler and more sturdy 'b_raw' sample.
%
% ------------------------------------------------------------------------
%
% Create local mysql database:
%
% $ mysql ...
% mysql> create database hello_database;
% mysql> use hello_database;
% mysql> create table hello_table (hello_text char(20));
% mysql> grant all privileges on hello_database.* to hello_username@localhost identified by 'hello_password';
% mysql> quit
%
% On *nix build and run using the batch a_hello in folder samples/:
%
% $ ./a_hello
%
% - or - 
%
% Make emysql and start this sample directly, along these lines:
%
% $ cd Emysql
% $ make
% $ cd samples
% $ erlc a_hello.erl
% $ erl -pa ../ebin -s a_hello run -s init stop -noshell
%
% ------------------------------------------------------------------------
%
% Expected output: [[<<"Hello World!">>]]
%
% ------------------------------------------------------------------------

-module(a_hello).
-export([run/0]).

run() ->

	crypto:start(),
	application:start(emysql),
	emysql:add_pool(hello_pool, [{size,1},
				     {user,"hello_username"},
				     {password,"hello_password"},
				     {database,"hello_database"},
				     {encoding,utf8}]),

	emysql:execute(hello_pool,
		<<"INSERT INTO hello_table SET hello_text = 'Hello World!'">>),

    { _, _, _, Result, _ } = emysql:execute(hello_pool,
    	<<"select hello_text from hello_table">>),

	io:format("~n~p~n", [Result]),

    ok.