updating usage in readme

README.markdown

@@ -0,0 +1,71 @@
+## Usage
+
+### Start the application
+
+	application:start(emysql).
+
+### Add a pool
+emysql:add\_pool(PoolName, PoolSize, Username, Password, Host, Port, Database, Encoding) -> ok | {error, pool\_already\_exists}  
+PoolName = atom()  
+PoolSize = integer()  
+Username = string()  
+Password = string()  
+Host = string()  
+Port = integer()  
+Database = string()  
+Encoding = atom()  
+
+	emysql:add_pool(mypoolname, 1, "username", "mypassword", "localhost", 3306, "mydatabase", utf8).
+
+### Record Types
+	-record(ok_packet, {seq_num, affected_rows, insert_id, status, warning_count, msg}).
+	-record(error_packet, {seq_num, code, msg}).
+	-record(result_packet, {seq_num, field_list, rows, extra}).
+
+### Executing SQL statements
+emysql:execute(PoolName, Statement) -> result\_packet() | ok\_packet() | error\_packet()  
+PoolName = atom()  
+Statement = string() | binary()  	
+
+	emysql:execute(mypoolname, <<"SELECT * from mytable">>).
+	#result_packet{field_list=[...], rows=[...]}
+
+	emysql:execute(mypoolname, <<"UPDATE mytable SET bar = 'baz' WHERE id = 1">>).
+	#ok_packet{affected_rows=1}
+
+### Executing prepared statements
+emysql:prepare(StmtName, Statement) -> ok  
+StmtName = atom()  
+Statement = binary() | string()  
+
+	emysql:prepare(my_stmt, <<"SELECT * from mytable WHERE id = ?">>).
+	ok
+
+emysql:execute(StmtName, Args) -> result\_packet() | ok\_packet() | error\_packet()  
+StmtName = atom()  
+Args = [term()]  
+
+	emysql:execute(my_stmt, [1]).
+	#result_packet{field_list=[...], rows=[...]}
+
+### Converting Row Data To Records
+emysql\_util:as\_record(ResultPacket, RecordName, Fields) -> Result  
+ResultPacket = result\_packet()  
+RecordName = atom() (the name of the record to generate)  
+Fields = [atom()] (the field names to generate for each record)  
+Result = [record()]  
+
+	-module(fetch_example).
+	-record(foo, {bar, baz, bat}).
+
+	fetch_foo() ->
+	   Result = emysql:execute(pool1, <<"select bar, baz, bat from foo">>),
+	   Recs = emysql_util:as_record(Result, foo, record_info(fields, foo)),
+	   [begin
+		  io:format("foo: ~p, ~p, ~p~n", [Foo#foo.bar, Foo#foo.baz, Foo#foo.bat])
+	    end || Foo <- Recs].
+
+### TODO:
+* decrementing pool size could close sockets that are in use
+* spawn individual conn\_mgr gen\_server processes for each pool
+* allow row results to be returned as binary