pdodbDb -- Simple PDO wrapper with prepared statements

Table of Contents

Initialization
Insert Query
Update Query
Select Query
Delete Query
Running raw SQL queries
Where Conditions
Joining Tables
Subqueries
Prepared Queries

Installation

To utilize this class, first import sql_builder.php into your project, and require it then import pdodb.php into your project, and require it.

require_once ('sql_builder.php');
require_once ('pdodb.php');

Initialization

Simple initialization: make sure the following constants are defined DB_SERVER,DB_NAME,DB_USER,DB_PASS, the initialization is automated with variable name $db

$db = new PDOdb(DB_SERVER,DB_NAME,DB_USER,DB_PASS);

SQLITE initialization: provide the filepath to your sqlite db file as the first param only, the file does not have to exist to be passed

$db = new PDOdb('mysqlitedb');

Also it is possible to reuse already connected pdodb object:

$pdodb = new pdodb ('host', 'username', 'password', 'databaseName');
$db = new pdodbDb ($pdodb);

If you need to get already created pdodb object from another class or function use

    Class myclass {
        use PDOdbRef;

        function __construct() {
            $this->__db_instance_ref(); // public attribute $this->db has be created
        }
    }
    ...
    function myfunc () {
        global $db;
        // global $db var imported to local
    }

Insert Query

Simple example

$db->insert('users', [$username, $email], 'username,email');
if ($db->execute())
    echo 'user was created. Id=' . $db->last_insert_id();
else
    echo 'insert failed: ' . $db->error_info();

Insert with ignore

    $values = [$username, $email];
    $cols = 'username,email';

    $db->insert('users', $values, $cols, true);
    $db->execute();

Update Query

$data = [   'username'=>'emmanuel',
            'email'=>'eosobande@gmail.com'  ];

$db->where(['id', 1]); OR $db->where('id=1');
$db->update ('users', $data);
if ($db->execute())
    echo $db->row_count() . ' records were updated';
else
    echo 'update failed: ' . $db->error_info();

update() also support limit parameter:

$db->update('users', $data, 5);
// Gives: UPDATE users SET ... LIMIT 5

Select Query

After any select function calls amount or returned rows is stored in $count variable

$db->select('users'); 
$users = $db->fetch(); // contains an Array of all users
$users = $db->select('users', 10); //contains an Array 10 users

or select with custom columns set. Functions also could be used

$cols = "id,name,email";
$db->select("users", $cols);
$users = $db->fetch();

or select just one row

$db->where (["id", 1]);
$db->select('users');
$user = $db->fetch(PDOdb::_FETCH_ONE);
echo $user['id'];

or select one column value or function result

$db->select("users", "count(*)");
$count = $db->fetch(PDOdb::_FETCH_ONE_FIELD);
echo "{$count} users found";

or select one column with direct array acces:

$db->select("users", "username");
$usernames = $db->fetch(PDOdb::_FETCH_FIRST_FROM_EACH_ROW);
foreach ($usernames as $username) {
    echo $username.'<br>';
}

or select with keywords:

$keywords = [
    'limit'=>5,
    'order_by'=>'username',
    'offset'=>10,
    'group_by'=> '',
    'having'=> ''
]

$db->select("users", "login", $keywords);
$users = $db->fetch();

or select distinct

$db->select("users", "login", null, true);
$users = $db->fetch();

Running raw SQL queries

$db->raw_query('SELECT * from users');
$users = $db->fetch();

Where Methods

each $db->where() paramenter must be either an array or a string

Regular = operator with variables:

$db->where (['id', 1]);
$db->select ('users');
// Gives: SELECT * FROM users WHERE id=1 AND login='admin';

$db->where (['id', 1], ['username', 'emmanuel', '=']);
$results = $db->select ('users');
// Gives: SELECT * FROM users WHERE id=1 AND username='emmanuel';

$db->where ('id=1', ['username', 'emmanuel', '=', 'or']);
$results = $db->select ('users');
// Gives: SELECT * FROM users WHERE id=1 OR username='emmanuel';

BETWEEN / NOT BETWEEN:

$db->where (['id', [4, 20], 'between']);
$db->select('users');
$db->execute();
// Gives: SELECT * FROM users WHERE id BETWEEN 4 AND 20

IN / NOT IN:

$db->where (['id', [4, 1, 2, 3, 6 20], 'in']);
$db->select('users');
$db->execute();

// Gives: SELECT * FROM users WHERE id IN (1, 5, 27, -1, 'd');

Also you can use raw where conditions:

$db->where ("DATE(created) = DATE(lastLogin)");
$db->select("users");
$db->execute();

Delete Query with limiter

$db->where(['id', 1]);
$db->delete('users', 1);
if($db->execute()) echo 'successfully deleted';

Join table products with table users with LEFT JOIN by user_id

JOIN method

$tables = [
    ['products', 'as'='p'],
    ['users', 'as=>'u', 'join'=>'left', 'on'=>'p.user_id=u.user_id']
];

$db->select($tables);
$products = $db->fetch();
print_r ($products);

Subqueries

$sq = $db->sub_query();
$sq->select("users", 'user_id');

$db->where(['user_id', $sq, 'in']);
$db->select('products');
var_dump($db->fetch());

Prepared queries with placeholders

    $db->select('users');
    $users = $db->fetch();

    $db->where('user_id=?');
    $db->select('products', 'COUNT(*)');
    $db->prepare();

    foreach ($users as $key => $user) {
        $db->execute([$user['user_id']], TRUE);
        $users[$key]['product_count'] = $db->fetch(PDOdb::_FETCH_ONE_FIELD, FALSE);
    }

    print_r($users);