1: <?php
  2: /**
  3:  * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
  4:  * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
  5:  *
  6:  * Licensed under The MIT License
  7:  * For full copyright and license information, please see the LICENSE.txt
  8:  * Redistributions of files must retain the above copyright notice.
  9:  *
 10:  * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 11:  * @link          https://cakephp.org CakePHP(tm) Project
 12:  * @since         3.0.0
 13:  * @license       https://opensource.org/licenses/mit-license.php MIT License
 14:  */
 15: namespace Cake\Database\Driver;
 16: 
 17: use Cake\Database\Query;
 18: use Cake\Database\Statement\PDOStatement;
 19: use PDO;
 20: 
 21: /**
 22:  * PDO driver trait
 23:  */
 24: trait PDODriverTrait
 25: {
 26: 
 27:     /**
 28:      * Instance of PDO.
 29:      *
 30:      * @var \PDO|null
 31:      */
 32:     protected $_connection;
 33: 
 34:     /**
 35:      * Establishes a connection to the database server
 36:      *
 37:      * @param string $dsn A Driver-specific PDO-DSN
 38:      * @param array $config configuration to be used for creating connection
 39:      * @return bool true on success
 40:      */
 41:     protected function _connect($dsn, array $config)
 42:     {
 43:         $connection = new PDO(
 44:             $dsn,
 45:             $config['username'],
 46:             $config['password'],
 47:             $config['flags']
 48:         );
 49:         $this->connection($connection);
 50: 
 51:         return true;
 52:     }
 53: 
 54:     /**
 55:      * Returns correct connection resource or object that is internally used
 56:      * If first argument is passed, it will set internal connection object or
 57:      * result to the value passed
 58:      *
 59:      * @param null|\PDO $connection The PDO connection instance.
 60:      * @return \PDO connection object used internally
 61:      */
 62:     public function connection($connection = null)
 63:     {
 64:         if ($connection !== null) {
 65:             $this->_connection = $connection;
 66:         }
 67: 
 68:         return $this->_connection;
 69:     }
 70: 
 71:     /**
 72:      * Disconnects from database server
 73:      *
 74:      * @return void
 75:      */
 76:     public function disconnect()
 77:     {
 78:         $this->_connection = null;
 79:     }
 80: 
 81:     /**
 82:      * Checks whether or not the driver is connected.
 83:      *
 84:      * @return bool
 85:      */
 86:     public function isConnected()
 87:     {
 88:         if ($this->_connection === null) {
 89:             $connected = false;
 90:         } else {
 91:             try {
 92:                 $connected = $this->_connection->query('SELECT 1');
 93:             } catch (\PDOException $e) {
 94:                 $connected = false;
 95:             }
 96:         }
 97: 
 98:         return (bool)$connected;
 99:     }
100: 
101:     /**
102:      * Prepares a sql statement to be executed
103:      *
104:      * @param string|\Cake\Database\Query $query The query to turn into a prepared statement.
105:      * @return \Cake\Database\StatementInterface
106:      */
107:     public function prepare($query)
108:     {
109:         $this->connect();
110:         $isObject = $query instanceof Query;
111:         $statement = $this->_connection->prepare($isObject ? $query->sql() : $query);
112: 
113:         return new PDOStatement($statement, $this);
114:     }
115: 
116:     /**
117:      * Starts a transaction
118:      *
119:      * @return bool true on success, false otherwise
120:      */
121:     public function beginTransaction()
122:     {
123:         $this->connect();
124:         if ($this->_connection->inTransaction()) {
125:             return true;
126:         }
127: 
128:         return $this->_connection->beginTransaction();
129:     }
130: 
131:     /**
132:      * Commits a transaction
133:      *
134:      * @return bool true on success, false otherwise
135:      */
136:     public function commitTransaction()
137:     {
138:         $this->connect();
139:         if (!$this->_connection->inTransaction()) {
140:             return false;
141:         }
142: 
143:         return $this->_connection->commit();
144:     }
145: 
146:     /**
147:      * Rollback a transaction
148:      *
149:      * @return bool true on success, false otherwise
150:      */
151:     public function rollbackTransaction()
152:     {
153:         $this->connect();
154:         if (!$this->_connection->inTransaction()) {
155:             return false;
156:         }
157: 
158:         return $this->_connection->rollback();
159:     }
160: 
161:     /**
162:      * Returns a value in a safe representation to be used in a query string
163:      *
164:      * @param mixed $value The value to quote.
165:      * @param string $type Type to be used for determining kind of quoting to perform
166:      * @return string
167:      */
168:     public function quote($value, $type)
169:     {
170:         $this->connect();
171: 
172:         return $this->_connection->quote($value, $type);
173:     }
174: 
175:     /**
176:      * Returns last id generated for a table or sequence in database
177:      *
178:      * @param string|null $table table name or sequence to get last insert value from
179:      * @param string|null $column the name of the column representing the primary key
180:      * @return string|int
181:      */
182:     public function lastInsertId($table = null, $column = null)
183:     {
184:         $this->connect();
185: 
186:         return $this->_connection->lastInsertId($table);
187:     }
188: 
189:     /**
190:      * Checks if the driver supports quoting, as PDO_ODBC does not support it.
191:      *
192:      * @return bool
193:      */
194:     public function supportsQuoting()
195:     {
196:         $this->connect();
197: 
198:         return $this->_connection->getAttribute(PDO::ATTR_DRIVER_NAME) !== 'odbc';
199:     }
200: }
201: