4.2 KiB
Query
A query builder/database abstraction layer, using prepared statements for security.
Requirements
- PDO extensions for the databases you wish to use (unless it's Firebird, in which case, the interbase extension is required)
- Supported version of PHP (Older versions may work, but are not supported)
Databases Supported
- Firebird (via interbase extension)
- MySQL
- PostgreSQL
- SQLite
Including Query in your application
- Install via composer and include
vendor/autoload.php
or - 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', // mysql, pgsql, firebird, sqlite
'host' => 'localhost', // address or socket
'user' => 'root',
'pass' => '',
'port' => '3306',
'database' => 'test_db',
// Only required for
// 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.
<?php
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
<?php
// 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 Query Builder class. However, it does not implement the update_batch
or caching methods. For specific query builder methods, see the class documentation.
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:
<?php
$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 PostgreSQL database):
SELECT "id", "key" AS "k", "val"
FROM "table" "t"
WHERE "k" > ?
OR "id" != ?
ORDER BY "val" DESC
LIMIT 3 OFFSET 1
To retrieve the results of a query, use the PDO method fetch and/or fetchAll.
<?php
$query = $db->get('table_name');
$results = $query->fetchAll(PDO::FETCH_ASSOC);
Inserting / Updating
An example of an insert query:
<?php
$query = $db->set('foo', 'bar')
->set('foobar', 'baz')
->where('foo !=', 'bar')
->insert('table');
An example of an update query:
<?php
$query = $db->set('foo', 'bar')
->set('foobar', 'baz')
->where('foo !=', 'bar')
->update('table');
The set
method can also take an array as a parameter, instead of setting individual values.