Copyright (c) 2014, 2015, 2016 Gregoire Lejeune
Version: 0.0.1
Authors: Gregoire Lejeune (gregoire.lejeune@free.fr
).
A simple ORM for Erlang
To use texas
in you application, just add the following line in your rebar.config
file :
{texas, ".*", {git, "https://github.com/emedia-project/texas", "master"}},
You also need a driver :
-
PostgreSQL : https://github.com/emedia-project/texas_pgsql
With texas
a table is defined as an Erlang module. The name of the table is the name of the module.
-module(my_table).
To generate the table, you must use the texas_transform
parser. To do so, just add the following line under the module declaration :
-compile([{parse_transform, texas_transform}]).
Then you define the columns using -field
. This directive takes a tuple of two elements. The first element is an atom corresponding to the name of the column. The second element is a key list accepting the following options :
-
{type, Type}
whereType
=integer
|string
|float
|date
|time
|datetime
-
{autoincrement, Auto}
whereAuto
=true
|false
(default:false
) -
{len, Size}
whereSize
is a number or a tuple (default:null
) -
{not_null, NN}
whereNN
=true
|false
(default:false
) -
{unique, Uniq}
whereUniq
=true
|false
(default:false
) -
{default, Def}
whereDef
=item()
(default:null
)
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({name, [{type, string}, {len, 128} ]}).
Each table involved in an associations must have a column id
!!!
accounts.erl
:
-module(accounts).
-compile([{parse_transform, texas_transform}]).
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({account_number, [{type, string}, {len, 255} ]}).
-field({supplier, [{belongs_to, suppliers} ]}).
suppliers.erl
:
-module(suppliers).
-compile([{parse_transform, texas_transform}]).
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({name, [{type, string}, {len, 255} ]}).
-field({account, [{has_one, accounts} ]}).
orders.erl
:
-module(orders).
-compile([{parse_transform, texas_transform}]).
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({order_date, [{type, string}, {len, 255} ]}).
-field({customer, [{belongs_to, customers} ]}).
customers.erl
:
-module(customers).
-compile([{parse_transform, texas_transform}]).
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({name, [{type, string}, {len, 255} ]}).
-field({orders, [{has_many, orders} ]}).
parts.erl
:
-module(parts).
-compile([{parse_transform, texas_transform}]).
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({part_number, [{type, string}, {len, 255} ]}).
-field({assemblies, [{habtm, assemblies} ]}).
assemblies.erl
:
-module(assemblies).
-compile([{parse_transform, texas_transform}]).
-field({id, [{type, integer}, {autoincrement, true}]}).
-field({name, [{type, string}, {len, 255} ]}).
-field({parts, [{habtm, parts} ]}).
There is two ways to connect to a database :
-
You can use
texas:connect/1
. This function's parameter is a connection string (driver://[login[:password]@[server[:port]]/[path][?options]
). -
Or, you can use
texas:connect/0
. In this case, you must add the connections informations in your config file.
The config file accept the following texas
options :
-
uri
: give the connection string -
autoconnect
:true
|false
- If this option is set totrue
the connection will be automatic on call oftexas:start/0
which will then return{ok, Conn}
or{error, Error}
. -
tables
: give a list of tables (see bellow).
Here is a configuration example:
[
{texas, [
{uri, "sqlite:///sample.db"},
{autoconnect, true},
{tables, [address, device, pipo, users]}
]}
].
You can create table using the texas:create_table/2
function. This fonction takes two parameters:
-
A
connection
(returned bytexas:connect
). -
A table module name.
If you have a configuration file, you can create your tables with rebar. To do so, ensure that's all your tables are referenced in the list of the tables
option. Add the texas_rebar
plugin in your rebar.config
:
{plugins, [texas_rebar]}.
Finally, run
rebar db-create
The texas_rebar
plugin assume that's your configuration file is config/sys.config
. If not, you can specify the path to the config file, using the texas
option :
rebar db-create texas=path/to/my.config
You can also drop tables with rebar, using the db-drop
command :
rebar db-drop [texas=path/to/my.config]
texas:start(),
% Initialize connection
Conn = texas:connect("sqlite:///sample.db"),
% Create tables (if not exist)
ok = texas:create_table(Conn, person),
ok = texas:create_table(Conn, address),
% Create a new address
Address = address:new(Conn, [{street, "21 jump street"}, {city, "New Orleans"}, {zip, "70112"}]).
Address1 = Address:insert().
% Create a new Person and insert it
Person = person:new(Conn, [{name, "Greg"}, {mail, "gregoire.lejeune"}]),
Person1 = Person:address(Address1),
Person2 = Person:insert(),
io:format("person created with ID #~p~n", [Person2:id()]),
% Find
Person3 = person:find(Conn, first, [{where, [{name, "=", "Greg"}]}]),
Address2 = Person3:address(),
PersonsAtAddress = Address2:people(),
% Update
Person4 = Person3:update([{name, "Bob"]]),
% Delete
ok = Person4:delete().
Copyright (c) 2014, 2015, 2016, Gregoire Lejeune
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
texas |