Update README.md

adds examples and value representation

README.md

@@ -32,27 +32,28 @@ Opts = [{host, "localhost"}, {user, "foo"}, {password, "hello"},
 %% A query returning results
 {ok, ColumnNames, Rows} = mysql:query(Pid, <<"SELECT * FROM mytable">>),
 
-%% An "anonymous prepared statement" with parameters, prepared and executed
-%% on the fly. NOT IMPLEMENTED YET.
-{ok, ColumnNames, Rows} =
-    mysql:query(Pid, <<"SELECT * FROM mytable WHERE id=?">>, [42]),
-
 %% A query not returning any rows just returns ok.
-ok = mysql:query(Pid, "INSERT INTO mytable (foo, bar) VALUES (?, ?)",
-                 [1, 42]),
+ok = mysql:query(Pid, "INSERT INTO mytable (foo, bar) VALUES (1, 42)"),
+
+%% Named prepared statements. Maybe the function should be execute/3
+%% instead of query/3.
+{ok, foo} = mysql:prepare(Pid, "SELECT * FROM mytable WHERE id=?", foo),
+{ok, Columns, Rows} = mysql:query(Pid, foo, [42]),
+
+%% Unnamed prepared statements. The function query/3 will maybe be
+%% renamed to execute/3.
+{ok, StmtId} = mysql:prepare(Pid, "SELECT * FROM mytable WHERE id=?"),
+{ok, Columns, Rows} = mysql:query(Pid, StmtId, [42]).
 
 %% Separate calls to fetch more info about the last query
 LastInsertId = mysql:insert_id(Pid),
 AffectedRows = mysql:affected_rows(Pid),
 WarningCount = mysql:warning_count(Pid),
 
-%% Named prepared statements
-{ok, foo} = mysql:prepare(Pid, "SELECT * FROM mytable WHERE id=?", foo),
-{ok, Columns, Rows} = mysql:execute(Pid, foo, [42]),
-
-%% Unnamed prepared statements
-{ok, StmtId} = mysql:prepare(Pid, "SELECT * FROM mytable WHERE id=?"),
-{ok, Columns, Rows} = mysql:execute(Pid, StmtId, [42]).
+%% An "anonymous prepared statement" with parameters, prepared and executed
+%% on the fly. NOT IMPLEMENTED YET.
+{ok, ColumnNames, Rows} =
+    mysql:query(Pid, <<"SELECT * FROM mytable WHERE id=?">>, [42]),
 
 %% Transactions: If an exception (throw/error/exit) occurs, the transaction
 %% is rollbacked without catching the exception. This means transactions are
@@ -73,6 +74,20 @@ catch
 end.
 ```
 
+Value representation
+--------------------
+
+ MySQL              | Erlang                  | Examples
+--------------------|-------------------------|-------------------
+INT, TINYINT, etc.  | integer()               | 42
+VARCHAR, TEXT, etc. | iodata()                | <<"foo">>, "bar"
+FLOAT, DOUBLE       | float()                 | 3.14
+DECIMAL             | binary()                | <<"3.140">>
+DATETIME, TIMESTAMP | calendar:datetime()     | {{2014, 11, 18}, {10, 22, 36}}
+DATE                | calendar:date()         | {2014, 11, 18}
+TIME                | {time, calendar:time()} | {time, {10, 22, 36}} -- **will probably change**
+NULL                | null                    | null
+
 Problems with Emysql
 --------------------