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<?php
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/**
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* Base Database Access Object
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* Members must be public in order to be called in data object
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* The following databases are supported:
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*
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* - [http://mysql.com MySQL]
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* - [http://postgresql.org PostgreSQL]
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* - [http://sqlite.org SQLite]
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*
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* @author Zhou Yuan <yuanzhou19@gmail.com>
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* @link http://www.infopotato.com/
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* Original code from {@link http://php.justinvincent.com Justin Vincent (justin@visunet.ie)}
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* @copyright Copyright © 2009-2011 Zhou Yuan
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* @license http://www.opensource.org/licenses/mit-license.php MIT Licence
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*/
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// Must define the constants out of the class
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// Can not define them as class const
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define('FETCH_OBJ', 'FETCH_OBJ');
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define('FETCH_ASSOC', 'FETCH_ASSOC');
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define('FETCH_NUM', 'FETCH_NUM');
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class Base_DAO {
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/**
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* Query result
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*
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* @var array
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*/
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public $query_result = array();
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/**
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* Gets the ID generated by the last INSERT query
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*
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* @var integer
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*/
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public $last_insert_id;
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/**
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* Constructor
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*
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* Closing isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
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* Allow the user to perform a connect at the same time as initialising the this class
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*/
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public function __construct(array $config = NULL) {}
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/**
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* Escapes special characters in a string for use in an SQL statement,
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* taking into account the current charset of the connection
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*/
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public function escape($string) {}
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/**
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* Overridden by specific DB class
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* USAGE: prepare( string $query [, array $params ] )
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* $query - SQL query WITHOUT any user-entered parameters. Replace parameters with "?"
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* e.g. $query = "SELECT date from history WHERE login = ?"
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* $params - array of parameters
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*
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* Example:
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* prepare( "SELECT secret FROM db WHERE login = ?", array($login) );
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* prepare( "SELECT secret FROM db WHERE login = ? AND password = ?", array($login, $password) );
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* That will result safe query to RDBMS with escaped $login and $password.
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*/
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public function prepare($query, array $params = NULL) {}
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/**
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* Perform SQL query and try to determine result value
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* Overridden by specific DB class
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* The query string should not end with a semicolon
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*
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* @return int Number of rows affected/selected or false on error
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*/
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public function exec_query($query) {}
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/**
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* Gets one single data cell from the database
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*
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* This function is very useful for evaluating query results within logic statements such as if or switch.
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* If the query generates more than one row the first row will always be used by default.
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* If the query generates more than one column the leftmost column will always be used by default.
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* Even so, the full resultset will be available within the array $db->query_result should you wish to use them.
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*
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* @param string $query SQL query. If null, use the result from the previous query.
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* @param int $x (optional) Column of value to return. Indexed from 0.
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* @param int $y (optional) Row of value to return. Indexed from 0.
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* @return string Database query result
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*/
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public function get_cell($query, $x = 0, $y = 0) {
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$return_val = '';
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$this->exec_query($query);
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if ($this->query_result !== array()) {
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if ($y >= count($this->query_result)) {
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halt('A System Error Was Encountered', 'The offset y you specified overflows', 'sys_error');
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}
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// Returns all the values from the input array and indexes numerically the array
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$values = array_values(get_object_vars($this->query_result[$y]));
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if ($x >= count($values)) {
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halt('A System Error Was Encountered', 'The offset x you specified overflows', 'sys_error');
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}
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if ($values[$x] !== '') {
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$return_val = $values[$x];
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}
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}
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return $return_val;
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}
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/**
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* Gets a single row from the database
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* If the query returns more than one row and no row offset is supplied the first row within the results set will be returned by default.
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*
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* @param string $query SQL query.
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* @param string $output (optional) one of FETCH_ASSOC | FETCH_NUM | FETCH_OBJ constants.
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* @param int $y (optional) Row to return if the query returns more than one row. Indexed from 0.
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* @return mixed Database query result in format specifed by $output
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*/
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public function get_row($query, $output = FETCH_OBJ, $y = 0) {
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$return_val = NULL;
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$this->exec_query($query);
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if ($this->query_result !== array()) {
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if ($y >= count($this->query_result)) {
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halt('A System Error Was Encountered', 'The offset y you specified overflows', 'sys_error');
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}
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if ($output == FETCH_OBJ) {
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$return_val = $this->query_result[$y];
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} elseif ($output == FETCH_ASSOC) {
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$return_val = get_object_vars($this->query_result[$y]);
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} elseif ($output == FETCH_NUM) {
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$return_val = array_values(get_object_vars($this->query_result[$y]));
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} else {
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halt('A System Error Was Encountered', " \$db->get_row() -- Output type must be one of: FETCH_OBJ, FETCH_ASSOC, FETCH_NUM", 'sys_error');
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}
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}
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return $return_val;
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}
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/**
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* Extracts one column as one dimensional array based on a column offset.
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*
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* If no offset is supplied the offset will defualt to column 0. I.E the first column.
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* If a null query is supplied the previous query results are used.
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*
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* @param string $query SQL query. If null, use the result from the previous query.
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* @param int $x Column to return. Indexed from 0.
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* @return array Database query result. Array indexed from 0 by SQL result row number.
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*/
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public function get_col($query, $x = 0) {
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$return_val = array();
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$this->exec_query($query);
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if ($this->query_result !== array()) {
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// Extract the column values
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$cnt = count($this->query_result);
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if ($x >= count(get_object_vars($this->query_result[0]))) {
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halt('A System Error Was Encountered', 'The offset x you specified overflows', 'sys_error');
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}
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for ($i = 0; $i < $cnt; $i++) {
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// Returns all the values from the input array and indexes numerically the array
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$values = array_values(get_object_vars($this->query_result[$i]));
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if ($values[$x] !== '') {
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$return_val[$i] = $values[$x];
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}
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}
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}
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return $return_val;
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}
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/**
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* Gets multiple rows of results from the database based on query and returns them as a multi dimensional array.
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*
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* Each element of the array contains one row of results and can be specified to be either an object, associative array or numerical array.
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* If no results are found then the function returns false enabling you to use the function within logic statements such as if.
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*
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* @param string $query SQL query.
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* @param string $output (optional) ane of FETCH_ASSOC | FETCH_ASSOC | FETCH_OBJ constants.
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* @return mixed Database query results
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*/
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public function get_all($query, $output = FETCH_OBJ) {
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$return_val = array();
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$this->exec_query($query);
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// Send back array of objects. Each row is an object
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if ($output == FETCH_OBJ) {
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$return_val = $this->query_result;
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} elseif ($output == FETCH_ASSOC || $output == FETCH_NUM) {
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if ($this->query_result) {
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$i = 0;
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// $row is object
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foreach($this->query_result as $row) {
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$return_val[$i] = get_object_vars($row);
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if ($output == FETCH_NUM) {
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$return_val[$i] = array_values($return_val[$i]);
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}
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$i++;
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}
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}
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}
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return $return_val;
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}
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/**
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* Begin Transaction
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*
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* @return bool
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*/
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public function trans_begin() {}
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/**
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* Commit Transaction
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*
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* @return bool
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*/
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public function trans_commit() {}
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/**
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* Rollback Transaction
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*
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* @return bool
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*/
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public function trans_rollback() {}
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}
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// End of file: ./system/core/base_dao.php
Page URI: http://www.infopotato.com/index.php/code/core/base_dao/