Query/README.md

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# Query
A query builder/database abstraction layer, using prepared queries for security.
[![Build Status](https://secure.travis-ci.org/timw4mail/Query.png)](http://travis-ci.org/timw4mail/Query)
## Requirements
* Pdo extensions for the databases you wish to use (unless it's Firebird, in which case, the interbase extension is required)
* PHP 5.2+
## Databases Supported
* Firebird (via interbase extension)
* MySQL
* PostgreSQL
* SQLite
* Others, via ODBC
## Including Query in your application
To include Query in your PHP project, just include the `autoload.php` file. This will automatically load the classes that are supported by the current PHP installation.
## Connecting
Create a connection array or object similar to this:
<?php
$params = array(
'type' => 'mysql',
'host' => 'localhost',
'user' => 'root',
'pass' => '',
'port' => '3306',
'database' => 'test_db',
// Only required
// SQLite or Firebird
'file' => '/path/to/db/file',
// Optional paramaters
'prefix' => 'tbl_', // Database table prefix
'alias' => 'old' // Connection name for the Query function
);
$db = Query($params);
The parameters required depend on the database.
### Query function
You can use the `Query()` function as a reference to the last connected database. E.g.
Query()->get('table_name');
or
$result = Query()->query($sql);
If the `alias` key is set in the parameters, you can refer to a specific database connection
// Set the alias in the connection parameters
$params['alias'] = 'old';
// Connect to the legacy database
Query('old')->query($sql);
### Running Queries
Query uses the same interface as CodeIgniter's [Active Record class](http://codeigniter.com/user_guide/database/active_record.html). However, it does not implement the `insert_batch`, `update_batch` or caching methods.
####You can also run queries manually.
To run a prepared statement, call
`$db->prepare_execute($sql, $params)`.
To run a plain query, `$db->query($sql)`
### Retrieving Results:
An example of a moderately complex query:
$query = $db->select('id, key as k, val')
->from('table t')
->where('k >', 3)
->or_where('id !=' 5)
->order_by('val', 'DESC')
->limit(3, 1)
->get();
This will generate a query similar to (with this being the output for a Postgres database):
SELECT "id", "key" AS "k", "val"
FROM "table" "t"
WHERE "k" > ?
OR "id" != ?
ORDER BY "val" DESC
LIMIT 3 OFFSET 1
To retreive the results of a query, use the PDO method [fetch](http://php.net/manual/en/pdostatement.fetch.php) and/or [fetchAll](http://php.net/manual/en/pdostatement.fetchall.php).
$query = $db->get('table_name');
$results = $query->fetchAll(PDO::FETCH_ASSOC);
### Inserting / Updating
An example of an insert query:
$query = $db->set('foo', 'bar')
->set('foobar', 'baz')
->where('foo !=', 'bar')
->insert('table');
An example of an update query:
$query = $db->set('foo', 'bar')
->set('foobar', 'baz')
->where('foo !=', 'bar')
->update('table');
The `set` method can also take an array as a paramater, instead of setting individual values.