MysqliDb -- Simple MySQLi wrapper with prepared statements

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### Table of Contents **[Initialization](#initialization)** **[Insert Query](#insert-query)** **[Update Query](#update-query)** **[Select Query](#select-query)** **[Delete Query](#delete-query)** **[Generic Query](#generic-query-method)** **[Raw Query](#raw-query-method)** **[Where Conditions](#where-method)** **[Order Conditions](#ordering-method)** **[Group Conditions](#grouping-method)** **[Properties Sharing](#properties-sharing)** **[Joining Tables](#join-method)** **[Subqueries](#subqueries)** **[EXISTS / NOT EXISTS condition](#exists--not-exists-condition)** **[Helper Functions](#helper-commands)** **[Transaction Helpers](#transaction-helpers)**

Initialization

To utilize this class, first import MysqliDb.php into your project, and require it.

require_once ('MysqliDb.php');

After that, create a new instance of the class.

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

Its also possible to set a table prefix:

$db->setPrefix ('my_');

Next, prepare your data, and call the necessary methods.

Insert Query

Simple example

$data = Array ("login" => "admin",
               "firstName" => "John",
               "lastName" => 'Doe'
)
$id = $db->insert('users', $data);
if($id)
    echo 'user was created. Id='.$id;

Insert with functions use

$data = Array(
	'login' => 'admin',
    'active' => true,
	'firstName' => 'John',
	'lastName' => 'Doe',
	'password' => $db->func('SHA1(?)',Array ("secretpassword+salt")),
	// password = SHA1('secretpassword+salt')
	'createdAt' => $db->now(),
	// createdAt = NOW()
	'expires' => $db->now('+1Y')
	// expires = NOW() + interval 1 year
	// Supported intervals [s]econd, [m]inute, [h]hour, [d]day, [M]onth, [Y]ear
);

$id = $db->insert ('users', $data);
if ($id)
    echo 'user was created. Id=' . $id;
else
    echo 'insert failed: ' . $db->getLastError();

Update Query

$data = Array (
	'firstName' => 'Bobby',
	'lastName' => 'Tables',
	'editCount' => $db->inc(2),
	// editCount = editCount + 2;
	'active' => $db->not()
	// active = !active;
);
$db->where ('id', 1);
if ($db->update ('users', $data))
    echo $db->count . ' records were updated';
else
    echo 'update failed: ' . $db->getLastError();

Select Query

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

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

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

$cols = Array ("id", "name", "email");
$users = $db->get ("users", null, $cols);
if ($db->count > 0)
    foreach ($users as $user) { 
        print_r ($user);
    }

or select just one row

$db->where ("id", 1);
$user = $db->getOne ("users");
echo $user['id'];

$stats = $db->getOne ("users", "sum(id), count(*) as cnt");
echo "total ".$stats['cnt']. "users found";

Delete Query

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

Generic Query Method

By default rawQuery() will filter out special characters so if you getting problems with it you might try to disable filtering function. In this case make sure that all external variables are passed to the query via bind variables

// filtering enabled
$users = $db->rawQuery('SELECT * from users where customerId=?', Array (10));
// filtering disabled
//$users = $db->rawQuery('SELECT * from users where id >= ?', Array (10), false);
foreach ($users as $user) {
    print_r ($user);
}

More advanced examples:

$params = Array(1, 'admin');
$users = $db->rawQuery("SELECT id, firstName, lastName FROM users WHERE id = ? AND login = ?", $params);
print_r($users); // contains Array of returned rows

// will handle any SQL query
$params = Array(10, 1, 10, 11, 2, 10);
$q = "(
    SELECT a FROM t1
        WHERE a = ? AND B = ?
        ORDER BY a LIMIT ?
) UNION (
    SELECT a FROM t2 
        WHERE a = ? AND B = ?
        ORDER BY a LIMIT ?
)";
$resutls = $db->rawQuery ($q, $params);
print_r ($results); // contains Array of returned rows

Where Method

This method allows you to specify where parameters of the query. WARNING: In order to use column to column comparisons only raw where conditions should be used as column name or functions cant be passed as a bind variable.

Regular == operator with variables:

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

Regular == operator with column to column comparison:

// WRONG
$db->where ('lastLogin', 'createdAt');
// CORRECT
$db->where ('lastLogin = createdAt');
$results = $db->get ('users');
// Gives: SELECT * FROM users WHERE lastLogin = createdAt;

$db->where ('id', 50, ">=");
// or $db->where ('id', Array ('>=' => 50));
$results = $db->get ('users');
// Gives: SELECT * FROM users WHERE id >= 50;

BETWEEN / NOT BETWEEN:

$db->where('id', Array (4, 20), 'BETWEEN');
// or $db->where ('id', Array ('BETWEEN' => Array(4, 20)));

$results = $db->get('users');
// Gives: SELECT * FROM users WHERE id BETWEEN 4 AND 20

IN / NOT IN:

$db->where('id', Array(1, 5, 27, -1, 'd'), 'IN');
// or $db->where('id', Array( 'IN' => Array(1, 5, 27, -1, 'd') ) );

$results = $db->get('users');
// Gives: SELECT * FROM users WHERE id IN (1, 5, 27, -1, 'd');

OR CASE

$db->where ('firstName', 'John');
$db->orWhere ('firstName', 'Peter');
$results = $db->get ('users');
// Gives: SELECT * FROM users WHERE firstName='John' OR firstName='peter'

NULL comparison:

$db->where ("lastName", NULL, '<=>');
$results = $db->get("users");
// Gives: SELECT * FROM users where lastName <=> NULL

Also you can use raw where conditions:

$db->where ("id != companyId");
$db->where ("DATE(createdAt) = DATE(lastLogin)");
$results = $db->get("users");

Or raw condition with variables:

$db->where ("(id = ? or id = ?)", Array(6,2));
$db->where ("login","mike")
$res = $db->get ("users");
// Gives: SELECT * FROM users WHERE (id = 2 or id = 2) and login='mike';

Optionally you can use method chaining to call where multiple times without referencing your object over an over:

$results = $db
	->where('id', 1)
	->where('login', 'admin')
	->get('users');

Ordering method

$db->orderBy("id","asc");
$db->orderBy("login","Desc");
$results = $db->get('users');
// Gives: SELECT * FROM users ORDER BY id ASC,login DESC;

Grouping method

$db->groupBy ("name");
$results = $db->get ('users');
// Gives: SELECT * FROM users GROUP BY name;

Join table products with table users with LEFT JOIN by tenantID

JOIN method

$db->join("users u", "p.tenantID=u.tenantID", "LEFT");
$db->where("u.id", 6);
$products = $db->get ("products p", null, "u.name, p.productName");
print_r ($products);

Properties sharing

Its is also possible to copy properties

Simple pagination example:

$db->where ("agentId", 10);
$db->where ("active", true);

$customers = $db->copy ();
$res = $customers->get ("customers", Array (10, 10));
// SELECT * FROM customers where agentId = 10 and active = 1 limit 10, 10

$res = $db->getOne ("customers", "count(id) as cnt");
echo "total records found: " . $res['cnt'];
// SELECT count(id) FROM users where agentId = 10 and active = 1

Subqueries

Subquery in selects:

$ids = $db->subQuery ();
$ids->where ("qty", 2, ">");
$ids->get ("products", null, "userId");

$db->where ("id", $ids, 'in');
$res = $db->get ("users");
// Gives SELECT * FROM users WHERE id IN (SELECT userId FROM products WHERE qty > 2)

Subquery in inserts:

$userIdQ = $db->subQuery ();
$userIdQ->where ("id", 6);
$userIdQ->getOne ("users", "name"),

$data = Array (
    "productName" => "test product",
    "userId" => $userIdQ,
    "lastUpdated" => $db->now()
);
$id = $db->insert ("products", $data);
// Gives INSERT INTO PRODUCTS (productName, userId, lastUpdated) values ("test product", (SELECT name FROM users WHERE id = 6), NOW());

###EXISTS / NOT EXISTS condition

$sub = $db->subQuery();
    $sub->where("company", 'testCompany');
    $sub->get ("users", null, 'userId');
$db->where (null, $sub, 'exists');
$products = $db->get ("products");
// Gives SELECT * FROM products WHERE EXISTS (select userId from users where company='testCompany')

Helper commands

Reconnect in case mysql connection died

if (!$db->ping())
    $db->connect()

Obtain an initialized instance of the class from another class

    $db = MysqliDb::getInstance();

Get last executed SQL query. Please note that function returns SQL query only for debugging purposes as its execution most likely will fail due missing quotes around char variables.

    $db->get('users');
    echo "Last executed query was ". $db->getLastQuery();

Transaction helpers

Please keep in mind that transactions are working on innoDB tables. Rollback transaction if insert fails:

$db->startTransaction();
...
if (!$db->insert ('myTable', $insertData)) {
    //Error while saving, cancel new record
    $db->rollback();
} else {
    //OK
    $db->commit();
}