Idiorm
http://j4mie.github.com/idiormandparis/
A lightweight nearly-zero-configuration object-relational mapper and fluent query builder for PHP5.
Tested on PHP 5.2.0+ - may work on earlier versions with PDO and the correct database drivers.
Released under a BSD license.
See Also: Paris, an Active Record implementation built on top of Idiorm.
Features
- Makes simple queries and simple CRUD operations completely painless.
- Gets out of the way when more complex SQL is required.
- Built on top of PDO.
- Uses prepared statements throughout to protect against SQL injection attacks.
- Requires no model classes, no XML configuration and no code generation: works out of the box, given only a connection string.
- Consists of just one class called
ORM
. Minimal global namespace pollution. - Database agnostic. Currently supports SQLite and MySQL. May support others, please give it a try!
- albertsun fork: Added a
SQL_CALC_FOUND_ROWS
method to add that clause to a query. MySQL only.
Changelog
1.0.0 - released 2010-12-01
- Initial release
1.1.0 - released 2011-01-24
- Add
is_dirty
method - Add basic query caching
- Add
distinct
method - Add
group_by
method
1.1.1 - release 2011-01-30
- Fix bug in quoting column wildcard. j4mie/paris#12
- Small documentation improvements
Philosophy
The Pareto Principle states that roughly 80% of the effects come from 20% of the causes. In software development terms, this could be translated into something along the lines of 80% of the results come from 20% of the complexity. In other words, you can get pretty far by being pretty stupid.
Idiorm is deliberately simple. Where other ORMs consist of dozens of classes with complex inheritance hierarchies, Idiorm has only one class, ORM
, which functions as both a fluent SELECT
query API and a simple CRUD model class. If my hunch is correct, this should be quite enough for many real-world applications. Let's face it: most of us aren't building Facebook. We're working on small-to-medium-sized projects, where the emphasis is on simplicity and rapid development rather than infinite flexibility and features.
You might think of Idiorm as a micro-ORM. It could, perhaps, be "the tie to go along with Slim's tux" (to borrow a turn of phrase from DocumentCloud). Or it could be an effective bit of spring cleaning for one of those horrendous SQL-littered legacy PHP apps you have to support.
Idiorm might also provide a good base upon which to build higher-level, more complex database abstractions. For example, Paris is an implementation of the Active Record pattern built on top of Idiorm.
Let's See Some Code
The first thing you need to know about Idiorm is that you don't need to define any model classes to use it. With almost every other ORM, the first thing to do is set up your models and map them to database tables (through configuration variables, XML files or similar). With Idiorm, you can start using the ORM straight away.
Setup
First, require
the Idiorm source file:
require_once 'idiorm.php';
Then, pass a Data Source Name connection string to the configure
method of the ORM class. This is used by PDO to connect to your database. For more information, see the PDO documentation.
ORM::configure('sqlite:./example.db');
You may also need to pass a username and password to your database driver, using the username
and password
configuration options. For example, if you are using MySQL:
ORM::configure('mysql:host=localhost;dbname=my_database');
ORM::configure('username', 'database_user');
ORM::configure('password', 'top_secret');
Also see "Configuration" section below.
Querying
Idiorm provides a fluent interface to enable simple queries to be built without writing a single character of SQL. If you've used jQuery at all, you'll be familiar with the concept of a fluent interface. It just means that you can chain method calls together, one after another. This can make your code more readable, as the method calls strung together in order can start to look a bit like a sentence.
All Idiorm queries start with a call to the for_table
static method on the ORM class. This tells the ORM which table to use when making the query.
Note that this method does not escape its query parameter and so the table name should not be passed directly from user input.
Method calls which add filters and constraints to your query are then strung together. Finally, the chain is finished by calling either find_one()
or find_many()
, which executes the query and returns the result.
Let's start with a simple example. Say we have a table called person
which contains the columns id
(the primary key of the record - Idiorm assumes the primary key column is called id
but this is configurable, see below), name
, age
and gender
.
Single records
Any method chain that ends in find_one()
will return either a single instance of the ORM class representing the database row you requested, or false
if no matching record was found.
To find a single record where the name
column has the value "Fred Bloggs":
$person = ORM::for_table('person')->where('name', 'Fred Bloggs')->find_one();
This roughly translates into the following SQL: SELECT * FROM person WHERE name = "Fred Bloggs"
To find a single record by ID, you can pass the ID directly to the find_one
method:
$person = ORM::for_table('person')->find_one(5);
Multiple records
Any method chain that ends in find_many()
will return an array of ORM class instances, one for each row matched by your query. If no rows were found, an empty array will be returned.
To find all records in the table:
$people = ORM::for_table('person')->find_many();
To find all records where the gender
is female
:
$females = ORM::for_table('person')->where('gender', 'female')->find_many();
Counting results
To return a count of the number of rows that would be returned by a query, call the count()
method.
$number_of_people = ORM::for_table('person')->count();
Filtering results
Idiorm provides a family of methods to extract only records which satisfy some condition or conditions. These methods may be called multiple times to build up your query, and Idiorm's fluent interface allows method calls to be chained to create readable and simple-to-understand queries.
Caveats
Only a subset of the available conditions supported by SQL are available when using Idiorm. Additionally, all the WHERE
clauses will be AND
ed together when the query is run. Support for OR
ing WHERE
clauses is not currently present.
These limits are deliberate: these are by far the most commonly used criteria, and by avoiding support for very complex queries, the Idiorm codebase can remain small and simple.
Some support for more complex conditions and queries is provided by the where_raw
and raw_query
methods (see below). If you find yourself regularly requiring more functionality than Idiorm can provide, it may be time to consider using a more full-featured ORM.
Equality: where
, where_equal
, where_not_equal
By default, calling where
with two parameters (the column name and the value) will combine them using an equals operator (=
). For example, calling where('name', 'Fred')
will result in the clause WHERE name = "Fred"
.
If your coding style favours clarity over brevity, you may prefer to use the where_equal
method: this is identical to where
.
The where_not_equal
method adds a WHERE column != "value"
clause to your query.
Shortcut: where_id_is
This is a simple helper method to query the table by primary key. Respects the ID column specified in the config.
Less than / greater than: where_lt
, where_gt
, where_lte
, where_gte
There are four methods available for inequalities:
- Less than:
$people = ORM::for_table('person')->where_lt('age', 10)->find_many();
- Greater than:
$people = ORM::for_table('person')->where_gt('age', 5)->find_many();
- Less than or equal:
$people = ORM::for_table('person')->where_lte('age', 10)->find_many();
- Greater than or equal:
$people = ORM::for_table('person')->where_gte('age', 5)->find_many();
String comparision: where_like
and where_not_like
To add a WHERE ... LIKE
clause, use:
$people = ORM::for_table('person')->where_like('name', '%fred%')->find_many();
Similarly, to add a WHERE ... NOT LIKE
clause, use:
$people = ORM::for_table('person')->where_not_like('name', '%bob%')->find_many();
Set membership: where_in
and where_not_in
To add a WHERE ... IN ()
or WHERE ... NOT IN ()
clause, use the where_in
and where_not_in
methods respectively.
Both methods accept two arguments. The first is the column name to compare against. The second is an array of possible values.
$people = ORM::for_table('person')->where_in('name', array('Fred', 'Joe', 'John'))->find_many();
Working with NULL
values: where_null
and where_not_null
To add a WHERE column IS NULL
or WHERE column IS NOT NULL
clause, use the where_null
and where_not_null
methods respectively. Both methods accept a single parameter: the column name to test.
Raw WHERE clauses
If you require a more complex query, you can use the where_raw
method to specify the SQL fragment for the WHERE clause exactly. This method takes two arguments: the string to add to the query, and an (optional) array of parameters which will be bound to the string. If parameters are supplied, the string should contain question mark characters (?
) to represent the values to be bound, and the parameter array should contain the values to be substituted into the string in the correct order.
This method may be used in a method chain alongside other where_*
methods as well as methods such as offset
, limit
and order_by_*
. The contents of the string you supply will be connected with preceding and following WHERE clauses with AND.
$people = ORM::for_table('person')
->where('name', 'Fred')
->where_raw('(`age` = ? OR `age` = ?)', array(20, 25))
->order_by_asc('name')
->find_many();
// Creates SQL:
SELECT * FROM `person` WHERE `name` = "Fred" AND (`age` = 20 OR `age` = 25) ORDER BY `name` ASC;
Note that this method only supports "question mark placeholder" syntax, and NOT "named placeholder" syntax. This is because PDO does not allow queries that contain a mixture of placeholder types. Also, you should ensure that the number of question mark placeholders in the string exactly matches the number of elements in the array.
If you require yet more flexibility, you can manually specify the entire query. See Raw queries below.
Limits and offsets
Note that these methods do not escape their query parameters and so these should not be passed directly from user input.
The limit
and offset
methods map pretty closely to their SQL equivalents.
$people = ORM::for_table('person')->where('gender', 'female')->limit(5)->offset(10)->find_many();
Ordering
Note that this method does not escape its query parameter and so this should not be passed directly from user input.
Two methods are provided to add ORDER BY
clauses to your query. These are order_by_desc
and order_by_asc
, each of which takes a column name to sort by.
$people = ORM::for_table('person')->order_by_asc('gender')->order_by_desc('name')->find_many();
Grouping
Note that this method does not escape it query parameter and so this should not by passed directly from user input.
To add a GROUP BY
clause to your query, call the group_by
method, passing in the column name. You can call this method multiple times to add further columns.
$poeple = ORM::for_table('person')->where('gender', 'female')->group_by('name')->find_many();
Result columns
By default, all columns in the SELECT
statement are returned from your query. That is, calling:
$people = ORM::for_table('person')->find_many();
Will result in the query:
SELECT * FROM `person`;
The select
method gives you control over which columns are returned. Call select
multiple times to specify columns to return.
$people = ORM::for_table('person')->select('name')->select('age')->find_many();
Will result in the query:
SELECT `name`, `age` FROM `person`;
Optionally, you may also supply a second argument to select
to specify an alias for the column:
$people = ORM::for_table('person')->select('name', 'person_name')->find_many();
Will result in the query:
SELECT `name` AS `person_name` FROM `person`;
Column names passed to select
are quoted automatically, even if they contain table.column
-style identifiers:
$people = ORM::for_table('person')->select('person.name', 'person_name')->find_many();
Will result in the query:
SELECT `person`.`name` AS `person_name` FROM `person`;
If you wish to override this behaviour (for example, to supply a database expression) you should instead use the select_expr
method. Again, this takes the alias as an optional second argument.
// NOTE: For illustrative purposes only. To perform a count query, use the count() method.
$people_count = ORM::for_table('person')->select('COUNT(*)', 'count')->find_many();
Will result in the query:
SELECT COUNT(*) AS `count` FROM `person`;
DISTINCT
To add a DISTINCT
keyword before the list of result columns in your query, add a call to distinct()
to your query chain.
$distinct_names = ORM::for_table('person')->distinct()->select('name')->find_many();
This will result in the query:
SELECT DISTINCT `name` FROM `person`;
Joins
Idiorm has a family of methods for adding different types of JOIN
s to the queries it constructs:
Methods: join
, inner_join
, left_outer_join
, right_outer_join
, full_outer_join
.
Each of these methods takes the same set of arguments. The following description will use the basic join
method as an example, but the same applies to each method.
The first two arguments are mandatory. The first is the name of the table to join, and the second supplies the conditions for the join. The recommended way to specify the conditions is as an array containing three components: the first column, the operator, and the second column. The table and column names will be automatically quoted. For example:
$results = ORM::for_table('person')->join('person_profile', array('person.id', '=', 'person_profile.person_id'))->find_many();
It is also possible to specify the condition as a string, which will be inserted as-is into the query. However, in this case the column names will not be escaped, and so this method should be used with caution.
// Not recommended because the join condition will not be escaped.
$results = ORM::for_table('person')->join('person_profile', 'person.id = person_profile.person_id')->find_many();
The join
methods also take an optional third parameter, which is an alias
for the table in the query. This is useful if you wish to join the table to itself to create a hierarchical structure. In this case, it is best combined with the table_alias
method, which will add an alias to the main table associated with the ORM, and the select
method to control which columns get returned.
$results = ORM::for_table('person')
->table_alias('p1')
->select('p1.*')
->select('p2.name', 'parent_name')
->join('person', array('p1.parent', '=', 'p2.id'), 'p2')
->find_many();
Raw queries
If you need to perform more complex queries, you can completely specify the query to execute by using the raw_query
method. This method takes a string and an array of parameters. The string should contain placeholders, either in question mark or named placeholder syntax, which will be used to bind the parameters to the query.
$people = ORM::for_table('person')->raw_query('SELECT p.* FROM person p JOIN role r ON p.role_id = r.id WHERE r.name = :role', array('role' => 'janitor')->find_many();
The ORM class instance(s) returned will contain data for all the columns returned by the query. Note that you still must call for_table
to bind the instances to a particular table, even though there is nothing to stop you from specifying a completely different table in the query. This is because if you wish to later called save
, the ORM will need to know which table to update.
Note that using raw_query
is advanced and possibly dangerous, and Idiorm does not make any attempt to protect you from making errors when using this method. If you find yourself calling raw_query
often, you may have misunderstood the purpose of using an ORM, or your application may be too complex for Idiorm. Consider using a more full-featured database abstraction system.
Getting data from objects
Once you've got a set of records (objects) back from a query, you can access properties on those objects (the values stored in the columns in its corresponding table) in two ways: by using the get
method, or simply by accessing the property on the object directly:
$person = ORM::for_table('person')->find_one(5);
// The following two forms are equivalent
$name = $person->get('name');
$name = $person->name;
You can also get the all the data wrapped by an ORM instance using the as_array
method. This will return an associative array mapping column names (keys) to their values.
The as_array
method takes column names as optional arguments. If one or more of these arguments is supplied, only matching column names will be returned.
$person = ORM::for_table('person')->create();
$person->first_name = 'Fred';
$person->surname = 'Bloggs';
$person->age = 50;
// Returns array('first_name' => 'Fred', 'surname' => 'Bloggs', 'age' => 50)
$data = $person->as_array();
// Returns array('first_name' => 'Fred', 'age' => 50)
$data = $person->as_array('first_name', 'age');
Updating records
To update the database, change one or more of the properties of the object, then call the save
method to commit the changes to the database. Again, you can change the values of the object's properties either by using the set
method or by setting the value of the property directly:
$person = ORM::for_table('person')->find_one(5);
// The following two forms are equivalent
$person->set('name', 'Bob Smith');
$person->age = 20;
// Syncronise the object with the database
$person->save();
Creating new records
To add a new record, you need to first create an "empty" object instance. You then set values on the object as normal, and save it.
$person = ORM::for_table('person')->create();
$person->name = 'Joe Bloggs';
$person->age = 40;
$person->save();
After the object has been saved, you can call its id()
method to find the autogenerated primary key value that the database assigned to it.
Checking whether a property has been modified
To check whether a property has been changed since the object was created (or last saved), call the is_dirty
method:
$name_has_changed = $person->is_dirty('name'); // Returns true or false
Deleting records
To delete an object from the database, simply call its delete
method.
$person = ORM::for_table('person')->find_one(5);
$person->delete();
Transactions
Idiorm doesn't supply any extra methods to deal with transactions, but it's very easy to use PDO's built-in methods:
// Start a transaction
ORM::get_db()->beginTransaction();
// Commit a transaction
ORM::get_db()->commit();
// Roll back a transaction
ORM::get_db()->rollBack();
For more details, see the PDO documentation on Transactions.
Configuration
Other than setting the DSN string for the database connection (see above), the configure
method can be used to set some other simple options on the ORM class. Modifying settings involves passing a key/value pair to the configure
method, representing the setting you wish to modify and the value you wish to set it to.
ORM::configure('setting_name', 'value_for_setting');
Database authentication details
Settings: username
and password
Some database adapters (such as MySQL) require a username and password to be supplied separately to the DSN string. These settings allow you to provide these values. A typical MySQL connection setup might look like this:
ORM::configure('mysql:host=localhost;dbname=my_database');
ORM::configure('username', 'database_user');
ORM::configure('password', 'top_secret');
PDO Driver Options
Setting: driver_options
Some database adapters require (or allow) an array of driver-specific configuration options. This setting allows you to pass these options through to the PDO constructor. For more information, see the PDO documentation. For example, to force the MySQL driver to use UTF-8 for the connection:
ORM::configure('driver_options', array(PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8'));
PDO Error Mode
Setting: error_mode
This can be used to set the PDO::ATTR_ERRMODE
setting on the database connection class used by Idiorm. It should be passed one of the class constants defined by PDO. For example:
ORM::configure('error_mode', PDO::ERRMODE_WARNING);
The default setting is PDO::ERRMODE_EXCEPTION
. For full details of the error modes available, see the PDO documentation.
Identifier quote character
Setting: identifier_quote_character
Set the character used to quote identifiers (eg table name, column name). If this is not set, it will be autodetected based on the database driver being used by PDO.
ID Column
By default, the ORM assumes that all your tables have a primary key column called id
. There are two ways to override this: for all tables in the database, or on a per-table basis.
Setting: id_column
This setting is used to configure the name of the primary key column for all tables. If your ID column is called primary_key
, use:
ORM::configure('id_column', 'primary_key');
Setting: id_column_overrides
This setting is used to specify the primary key column name for each table separately. It takes an associative array mapping table names to column names. If, for example, your ID column names include the name of the table, you can use the following configuration:
ORM::configure('id_column_overrides', array(
'person' => 'person_id',
'role' => 'role_id',
));
Query logging
Setting: logging
Idiorm can log all queries it executes. To enable query logging, set the logging
option to true
(it is false
by default).
When query logging is enabled, you can use two static methods to access the log. ORM::get_last_query()
returns the most recent query executed. ORM::get_query_log()
returns an array of all queries executed.
Query caching
Setting: caching
Idiorm can cache the queries it executes during a request. To enable query caching, set the caching
option to true
(it is false
by default).
When query caching is enabled, Idiorm will cache the results of every SELECT
query it executes. If Idiorm encounters a query that has already been run, it will fetch the results directly from its cache and not perform a database query.
Warnings and gotchas
-
Note that this is an in-memory cache that only persists data for the duration of a single request. This is not a replacement for a persistent cache such as Memcached.
-
Idiorm's cache is very simple, and does not attempt to invalidate itself when data changes. This means that if you run a query to retrieve some data, modify and save it, and then run the same query again, the results will be stale (ie, they will not reflect your modifications). This could potentially cause subtle bugs in your application. If you have caching enabled and you are experiencing odd behaviour, disable it and try again. If you do need to perform such operations but still wish to use the cache, you can call the
ORM::clear_cache()
to clear all existing cached queries. -
Enabling the cache will increase the memory usage of your application, as all database rows that are fetched during each request are held in memory. If you are working with large quantities of data, you may wish to disable the cache.