# PDO-database-class

PHP PDO Wrapper which utilizes PDO and prepared statements

<hr>

### Table of Contents

- **[Initialization](#initialization)**
- **[Insert Query](#insert-query)**
- **[Update Query](#update-query)**
- **[Select Query](#select-query)**
- **[Delete Query](#delete-query)**
- **[Pagination](#pagination)**
- **[Running raw SQL queries](#running-raw-sql-queries)**
- **[Query Keywords](#query-keywords)**
- **[Where Conditions](#where--having-methods)**
- **[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)**
- **[Has method](#has-method)**
- **[Helper Methods](#helper-methods)**
- **[Transaction Helpers](#transaction-helpers)**
- **[Error Helpers](#error-helpers)**

### Installation

To utilize this class, first import PDODb.php into your project, and require it.
PDODb requires PHP 5.5+ to work.

```php
require_once ('PDODb.php');
```

### Installation with composer

It is also possible to install library via composer
```
composer require tommyknocker/pdo-database-class
```

### Initialization

Simple initialization with utf8 charset set by default:
```php
$db = new PDODb('host', 'username', 'password', 'databaseName');
```

Advanced initialization:
```php
$db = new PDODb(['type' => 'mysql',
                 'host' => 'host',
                 'username' => 'username', 
                 'password' => 'password',
                 'dbname'=> 'databaseName',
                 'port' => 3306,
                 'prefix' => 'my_',
                 'charset' => 'utf8']);
```
table prefix, port and database charset params are optional.
If no charset should be set charset, set it to null

Also it is possible to reuse already connected pdo object:
```php
$pdo = new PDO('mysql:dbname=test;host=localhost', 'user', 'password');
$db = new PDODb($pdo);
```

If no table prefix were set during object creation its possible to set it later with a separate call:
```php
$db->setPrefix('my_');
```

If you need to get already created pdo object from another class or function use
```php
    function init() {
        // db staying private here
        $db = new PDODb('type', 'host', 'username', 'password', 'databaseName');
    }
    ...
    function myfunс() {
        // obtain db object created in init()
        $db = PDODb::getInstance();
        ...
    }
```

### Insert Query

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

Insert with functions use
```php
$data = [
	'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();
}
```

Insert with on duplicate key update
```php
$data = ["login" => "admin",
         "firstName" => "John",
         "lastName" => 'Doe',
         "createdAt" => $db->now(),
         "updatedAt" => $db->now(),
];
$updateColumns = ["updatedAt"];
$lastInsertId = "id";
$db->onDuplicate($updateColumns, $lastInsertId);
$id = $db->insert('users', $data);
```

### Replace Query

<a href='https://dev.mysql.com/doc/refman/5.0/en/replace.html'>Replace()</a> method implements same API as insert();

### Update Query

```php
$data = ['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->getRowCount() . ' records were updated';
} else {
    echo 'update failed: ' . $db->getLastError();
}
```

`update()` also support limit parameter:
```php
$db->update('users', $data, 10);
// Gives: UPDATE users SET ... LIMIT 10
```

### Select Query

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

```php
$cols = ["id", "name", "email"];
$users = $db->get("users", null, $cols);
if ($users) {
    foreach ($users as $user) { 
        print_r ($user);
    }
}
```

or select just one row

```php
$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";
```

or select one column value or function result

```php
$count = $db->getValue("users", "COUNT(*)");
echo "{$count} users found";
```

select one column value or function result from multiple rows:
```php
$logins = $db->getValue("users", "login", null);
// select login from users
$logins = $db->getValue("users", "login", 5);
// select login from users limit 5
foreach ($logins as $login) {
    echo $login;
}
```

You may use php 5.5+ generator feature with PDODb get(), rawQuery() methods just call useGenerator(true) method

Example:
```php
$result = $db->useGenerator(true)->get('users'); // $result will contain Generator object
if($result->current()) {
    foreach($result as $row) {
        print_r($row);
    }
}
```

### Pagination

Use paginate() instead of get() to fetch paginated result
```php
$page = 1;
// set page limit to 2 results per page. 20 by default
$db->pageLimit = 2;
$products = $db->paginate("products", $page);
echo "showing $page out of " . $db->totalPages;

```

### Defining a return type

To select a return type use setReturnType() method.
```php
// Array return type
$= $db->getOne("users");
echo $u['login'];
// Object return type
$u = $db->setReturnType(PDO::FETCH_OBJ)->getOne("users");
echo $u->login;
```

### Running raw SQL queries

```php
$users = $db->rawQuery('SELECT * FROM users WHERE id >= ?', [10]);
foreach ($users as $user) {
    print_r($user);
}

$users = $db->rawQuery('SELECT * FROM users WHERE name=:name', ['name' => 'user1']);
foreach ($users as $user) {
    print_r($user);
}
```
To avoid long if checks there are couple helper functions to work with raw query select results:

Get 1 row of results:
```php
$user = $db->rawQueryOne('SELECT * FROM users WHERE id=:id', [id => 10]);
echo $user['login'];
// Object return type
$user = $db->setReturnType(PDO::FETCH_OBJ)->rawQueryOne('SELECT * FROM users WHERE id=?', [10]);
echo $user->login;
```
Get 1 column value as a string:
```php
$password = $db->rawQueryValue('SELECT password FROM users WHERE id=? LIMIT 1', [10]);
echo "Password is {$password}";
NOTE: for a rawQueryValue() to return string instead of an array 'limit 1' should be added to the end of the query.
```
Get 1 column value from multiple rows:
```php
$logins = $db->rawQueryValue('SELECT login FROM users LIMIT 10');
foreach ($logins as $login) {
    echo $login;
}
```

More advanced examples:
```php
$params = [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 = [10, 1, 10, 11, 2, 10];
$query = "(
    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 ?
)";
$result = $db->rawQuery($query, $params);
print_r ($result); // contains array of returned rows
```

### Where / Having Methods

`where()`, `orWhere()`, `having()` and `orHaving()` methods allows you to specify where and having conditions of the query. All conditions supported by where() are supported by having() as well.

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

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


Regular == operator with column to column comparison:
```php
// WRONG
$db->where('lastLogin', 'createdAt');
// CORRECT
$db->where('lastLogin = createdAt');
$results = $db->get('users');
// Gives: SELECT * FROM users WHERE lastLogin = createdAt;
```

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

BETWEEN / NOT BETWEEN:
```php
$db->where('id', [4, 20], 'BETWEEN');

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

IN / NOT IN:
```php
$db->where('id', [1, 5, 27, -1, 'd'], 'IN');
$results = $db->get('users');
// Gives: SELECT * FROM users WHERE id IN (1, 5, 27, -1, 'd');
```

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

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


NULL comparison:
```php
$db->where("lastName", NULL, 'IS NOT');
$results = $db->get("users");
// Gives: SELECT * FROM users where lastName IS NOT NULL
```

Also you can use raw where conditions:
```php
$db->where("id != companyId");
$db->where("DATE(createdAt) = DATE(lastLogin)");
$results = $db->get("users");
```

Or raw condition with variables:
```php
$db->where("(id = ? OR id = ?)", [6,2]);
$db->where("login","mike")
$res = $db->get ("users");
// Gives: SELECT * FROM users WHERE (id = 6 OR id = 2) AND login='mike';
```


Find the total number of rows matched. Simple pagination example:
```php
$offset = 10;
$count = 15;
$users = $db->withTotalCount()->get('users', [$offset, $count]);
echo "Showing {$count} from {$db->totalCount}";
```

### Query Keywords

To add LOW PRIORITY | DELAYED | HIGH PRIORITY | IGNORE and the rest of the mysql keywords to INSERT (), REPLACE (), GET (), UPDATE (), DELETE() method or FOR UPDATE | LOCK IN SHARE MODE into SELECT ():
```php
$db->setQueryOption('LOW_PRIORITY')->insert($table, $param);
// GIVES: INSERT LOW_PRIORITY INTO table ...
```
```php
$db->setQueryOption('FOR UPDATE')->get('users');
// GIVES: SELECT * FROM USERS FOR UPDATE;
```

Also you can use an array of keywords:
```php
$db->setQueryOption(['LOW_PRIORITY', 'IGNORE'])->insert($table,$param);
// GIVES: INSERT LOW_PRIORITY IGNORE INTO table ...
```

Same way keywords could be used in SELECT queries as well:
```php
$db->setQueryOption('SQL_NO_CACHE');
$db->get("users");
// GIVES: SELECT SQL_NO_CACHE * FROM USERS;
```

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

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

### Delete Query

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


### Ordering method

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

Order by values example:
```php
$db->orderBy('userGroup', 'ASC', ['superuser', 'admin', 'users']);
$db->get('users');
// Gives: SELECT * FROM users ORDER BY FIELD (userGroup, 'superuser', 'admin', 'users') ASC;
```

If you are using setPrefix () functionality and need to use table names in orderBy() method make sure that table names are escaped with ``.

```php
$db->setPrefix("t_");
$db->orderBy("users.id","ASC");
$results = $db->get('users');
// WRONG: That will give: SELECT * FROM t_users ORDER BY users.id ASC;

$db->setPrefix("t_");
$db->orderBy("`users`.id", "ASC");
$results = $db->get('users');
// CORRECT: That will give: SELECT * FROM t_users ORDER BY t_users.id ASC;
```

### Grouping method

```php
$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

```php
$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

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

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

$cnt = $db->getValue("customers", "COUNT(id)");
echo "total records found: " . $cnt;
// SELECT COUNT(id) FROM users WHERE agentId = 10 AND active = 1
```

### Subqueries

Subquery init

Subquery init without an alias to use in inserts/updates/where Eg. (select * from users)
```php
$sq = $db->subQuery();
$sq->get("users");
```
 
A subquery with an alias specified to use in JOINs . Eg. (select * from users) sq
```php
$sq = $db->subQuery("sq");
$sq->get("users");
```

Subquery in selects:
```php
$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:
```php
$userIdQ = $db->subQuery ();
$userIdQ->where("id", 6);
$userIdQ->getOne("users", "name");

$data = ["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());
```

Subquery in joins:
```php
$usersQ = $db->subQuery("u");
$usersQ->where("active", 1);
$usersQ->get("users");

$db->join($usersQ, "p.userId=u.id", "LEFT");
$products = $db->get("products p", null, "u.login, p.productName");
print_r($products);
// SELECT u.login, p.productName FROM products p LEFT JOIN (SELECT * FROM t_users WHERE active = 1) u on p.userId=u.id;
```

### EXISTS / NOT EXISTS condition

```php
$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')
```

### Has method

A convenient function that returns TRUE if exists at least an element that satisfy the where condition specified calling the "where" method before this one.
```php
$db->where("user", $user);
$db->where("password", md5($password));
if($db->has("users")) {
    return "You are logged";
} else {
    return "Wrong user/password";
}
```

### Helper methods

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

Check if table exists:
```php
if ($db->tableExists('users')) {
    echo "hooray";
}
```

pdo::quote() wrapper:
```php
$escaped = $db->escape("' and 1=1");
```

### Transaction helpers

Please keep in mind that transactions are working on innoDB tables.
Rollback transaction if insert fails:
```php
$db->startTransaction();
...
if (!$db->insert('myTable', $insertData)) {
    //Error while saving, cancel new record
    $db->rollback();
} else {
    //OK
    $db->commit();
}
```

### Error helpers

After you executed a query you have options to check if there was an error. You can get the MySQL error string or the error code for the last executed query. 
```php
$db->where('login', 'admin')->update('users', ['firstName' => 'Jack']);

if ($db->getLastErrNo() === 0) {
    echo 'Update succesfull';
} else {
    echo 'Update failed. Error: '. $db->getLastError();
}
```