PHP中的MySQL访问类
我有一个MySQL连接类，如下所示：PHP中的MySQL访问类,php,mysql,database,Php,Mysql,Database,我有一个MySQL连接类，如下所示： class MySQLConnect { private $connection; private static $instances = 0; function __construct() { if(MySQLConnect::$instances == 0) { //Connect to MySQL server $this->conn
class MySQLConnect
{
private $connection;
private static $instances = 0;
function __construct()
{
if(MySQLConnect::$instances == 0)
{
//Connect to MySQL server
$this->connection = mysql_connect(MySQLConfig::HOST, MySQLConfig::USER, MySQLConfig::PASS)
or die("Error: Unable to connect to the MySQL Server.");
MySQLConnect::$instances = 1;
}
else
{
$msg = "Close the existing instance of the MySQLConnector class.";
die($msg);
}
}
public function singleQuery($query, $databasename)
{
mysql_select_db(MySQLConfig::DB, $this->connection)
or die("Error: Could not select database " . MySQLConfig::DB . " from the server.");
$result = mysql_query($query) or die('Query failed.');
return $result;
}
public function createResultSet($query, $databasename)
{
$rs = new MySQLResultSet($query, MySQLConfig::DB, $this->connection ) ;
return $rs;
}
public function close()
{
MySQLConnect::$instances = 0;
if(isset($this->connection) ) {
mysql_close($this->connection) ;
unset($this->connection) ;
}
}
public function __destruct()
{
$this->close();
}
}
class MySQLResultSet implements Iterator
{
private $query;
private $databasename;
private $connection;
private $result;
private $currentRow;
private $key = 0;
private $valid;
public function __construct($query, $databasename, $connection)
{
$this->query = $query;
//Select the database
$selectedDatabase = mysql_select_db($databasename, $connection)
or die("Error: Could not select database " . $this->dbname . " from the server.");
$this->result = mysql_query($this->query) or die('Query failed.');
$this->rewind();
}
public function getResult()
{
return $this->result;
}
// public function getRow()
// {
// return mysql_fetch_row($this->result);
// }
public function getNumberRows()
{
return mysql_num_rows($this->result);
}
//current() returns the current row
public function current()
{
return $this->currentRow;
}
//key() returns the current index
public function key()
{
return $this->key;
}
//next() moves forward one index
public function next()
{
if($this->currentRow = mysql_fetch_array($this->result) ) {
$this->valid = true;
$this->key++;
}else{
$this->valid = false;
}
}
//rewind() moves to the starting index
public function rewind()
{
$this->key = 0;
if(mysql_num_rows($this->result) > 0)
{
if(mysql_data_seek($this->result, 0) )
{
$this->valid = true;
$this->key = 0;
$this->currentRow = mysql_fetch_array($this->result);
}
}
else
{
$this->valid = false;
}
}
//valid returns 1 if the current position is a valid array index
//and 0 if it is not valid
public function valid()
{
return $this->valid;
}
}
if(!ImageCount::getCount())
{
//Do something
}
class MySQLConnect
{
private $connection;
private static $instances = 0;
function __construct()
{
if(MySQLConnect::$instances == 0)
{
//Connect to MySQL server
$this->connection = mysql_connect(MySQLConfig::HOST, MySQLConfig::USER, MySQLConfig::PASS)
or die("Error: Unable to connect to the MySQL Server.");
MySQLConnect::$instances = 1;
}
else
{
$msg = "Close the existing instance of the MySQLConnector class.";
die($msg);
}
}
public function singleQuery($query, $databasename)
{
mysql_select_db(MySQLConfig::DB, $this->connection)
or die("Error: Could not select database " . MySQLConfig::DB . " from the server.");
$result = mysql_query($query) or die('Query failed.');
return $result;
}
public function createResultSet($query, $databasename)
{
$rs = new MySQLResultSet($query, MySQLConfig::DB, $this->connection ) ;
return $rs;
}
public function close()
{
MySQLConnect::$instances = 0;
if(isset($this->connection) ) {
mysql_close($this->connection) ;
unset($this->connection) ;
}
}
public function __destruct()
{
$this->close();
}
}
class MySQLResultSet implements Iterator
{
private $query;
private $databasename;
private $connection;
private $result;
private $currentRow;
private $key = 0;
private $valid;
public function __construct($query, $databasename, $connection)
{
$this->query = $query;
//Select the database
$selectedDatabase = mysql_select_db($databasename, $connection)
or die("Error: Could not select database " . $this->dbname . " from the server.");
$this->result = mysql_query($this->query) or die('Query failed.');
$this->rewind();
}
public function getResult()
{
return $this->result;
}
// public function getRow()
// {
// return mysql_fetch_row($this->result);
// }
public function getNumberRows()
{
return mysql_num_rows($this->result);
}
//current() returns the current row
public function current()
{
return $this->currentRow;
}
//key() returns the current index
public function key()
{
return $this->key;
}
//next() moves forward one index
public function next()
{
if($this->currentRow = mysql_fetch_array($this->result) ) {
$this->valid = true;
$this->key++;
}else{
$this->valid = false;
}
}
//rewind() moves to the starting index
public function rewind()
{
$this->key = 0;
if(mysql_num_rows($this->result) > 0)
{
if(mysql_data_seek($this->result, 0) )
{
$this->valid = true;
$this->key = 0;
$this->currentRow = mysql_fetch_array($this->result);
}
}
else
{
$this->valid = false;
}
}
//valid returns 1 if the current position is a valid array index
//and 0 if it is not valid
public function valid()
{
return $this->valid;
}
}
if(!ImageCount::getCount())
{
//Do something
}
class ImageCount
{
public function getCount()
{
$mysqlConnector = new MySQLConnect();
$query = "SELECT * FROM images;";
$resultSet = $mysqlConnector->createResultSet($query, MySQLConfig::DB);
$mysqlConnector->close();
return $resultSet->getNumberRows();
}
}
class MySQLConnect
{
private $connection;
private static $instances = 0;
function __construct()
{
if(MySQLConnect::$instances == 0)
{
//Connect to MySQL server
$this->connection = mysql_connect(MySQLConfig::HOST, MySQLConfig::USER, MySQLConfig::PASS)
or die("Error: Unable to connect to the MySQL Server.");
MySQLConnect::$instances = 1;
}
else
{
$msg = "Close the existing instance of the MySQLConnector class.";
die($msg);
}
}
public function singleQuery($query, $databasename)
{
mysql_select_db(MySQLConfig::DB, $this->connection)
or die("Error: Could not select database " . MySQLConfig::DB . " from the server.");
$result = mysql_query($query) or die('Query failed.');
return $result;
}
public function createResultSet($query, $databasename)
{
$rs = new MySQLResultSet($query, MySQLConfig::DB, $this->connection ) ;
return $rs;
}
public function close()
{
MySQLConnect::$instances = 0;
if(isset($this->connection) ) {
mysql_close($this->connection) ;
unset($this->connection) ;
}
}
public function __destruct()
{
$this->close();
}
}
class MySQLResultSet implements Iterator
{
private $query;
private $databasename;
private $connection;
private $result;
private $currentRow;
private $key = 0;
private $valid;
public function __construct($query, $databasename, $connection)
{
$this->query = $query;
//Select the database
$selectedDatabase = mysql_select_db($databasename, $connection)
or die("Error: Could not select database " . $this->dbname . " from the server.");
$this->result = mysql_query($this->query) or die('Query failed.');
$this->rewind();
}
public function getResult()
{
return $this->result;
}
// public function getRow()
// {
// return mysql_fetch_row($this->result);
// }
public function getNumberRows()
{
return mysql_num_rows($this->result);
}
//current() returns the current row
public function current()
{
return $this->currentRow;
}
//key() returns the current index
public function key()
{
return $this->key;
}
//next() moves forward one index
public function next()
{
if($this->currentRow = mysql_fetch_array($this->result) ) {
$this->valid = true;
$this->key++;
}else{
$this->valid = false;
}
}
//rewind() moves to the starting index
public function rewind()
{
$this->key = 0;
if(mysql_num_rows($this->result) > 0)
{
if(mysql_data_seek($this->result, 0) )
{
$this->valid = true;
$this->key = 0;
$this->currentRow = mysql_fetch_array($this->result);
}
}
else
{
$this->valid = false;
}
}
//valid returns 1 if the current position is a valid array index
//and 0 if it is not valid
public function valid()
{
return $this->valid;
}
}
if(!ImageCount::getCount())
{
//Do something
}
谢谢。我不确定是否真的需要一个名为“ImageCount”的类。如果你要处理图像，我只需要一个名为“Image”的类，它有一个静态函数来获取所有图像的计数，还有一些其他函数来处理图像
另外，如果您试图在一个实例存在时创建一个新实例，那么返回现有实例而不是使用die（）停止该程序如何。嘿，Mike，实现自己的类来处理数据库连接没有什么问题，到目前为止您所拥有的一切都很好，然而，PHP已经提供了一个处理数据库连接的接口，而不管您连接到哪个数据库管理器。我建议您看看它，因为它几乎拥有处理查询、语句、结果集、错误等所需的所有功能 干杯，
M.嗨，加里，你的意思是：退回$this？我喜欢你的解决方案。对于每种类型的查询都有类，这开始让人有点不知所措。我按照你的建议制作了一个图像类。谢谢是的，我的意思是将任何子序列调用中已经创建的对象返回给构造函数。除非你真的想坚持你自己的实施——你也应该确保你考虑了法洛米尔的建议，你认为考虑弗洛米尔的选择是正确的。事实上，我同意这一点。谢谢你的帮助！我原本想构建自己的数据抽象，但PDO是一个更好的选择。这会让我节省很多时间！谢谢没问题-我很高兴这有帮助：）