PHP中使用匿名函数操作数据库的例子

define("userName","root"); define("password","root"); define("dbName","ahcdb"); define("hostName","localhost");

class BaseDao {

function getConnection() { $link = mysql_connect(hostName,userName,password); if (!$link) die("Could not connect: " . mysql_error()); if (!mysql_select_db(dbName)) die("Could not select database: " . mysql_error()); return $link; }

function setParams(& $sql,$params) {
if($params != null)
$sql = vsprintf($sql,array_map(function($n) {
if(is_int($n))
return (int)$n;
if(is_float($n))
return (float)$n;
if(is_string($n))
return "'".mysql_real_escape_string($n)."'";
return mysql_real_escape_string($n);
},$params));
}

function executeQuery($sql,$params,$callback = null) { $link = $this->getConnection(); $this->setParams($sql,$params); $return = null; if(($result = mysql_query($sql,$link)) != null) if($callback != null) $return = $callback($result,$link); if($link != null) mysql_close($link); if(!$result) die("Fatal Error: Invalid query '$sql' : " . mysql_error()); return $return; }

function getList($sql,$callback) {
return $this->executeQuery($sql,function($result,$link) use ($callback) {
$idx = 0;
$list = array();
while ($row = mysql_fetch_assoc($result))
if($callback != null)
$list[$idx] = $callback($idx++,$row);
return $list;
});
}

function getSingle($sql,$link) use ($callback) {
if ($row = mysql_fetch_assoc($result))
$obj = $callback($row);
return $obj;
});
}
}

class Example { var $id; var $name;

function Example($id,$name){
$this->id = $id;
$this->name = $name;
}

function setId($id){
$this->id = $id;
}
}

class ExampleDao extends BaseDao {

function getAll(){
return parent::getList("select * from nodes",null,function($idx,$row) {
return new Example($row["id"],$row["name"]);
});
}

function load($id){
return parent::getSingle("select * from nodes where id = %1$s",array($id),function($row) {
return new Example($row["id"],$row["name"]);
});
}

function update($example){
return parent::executeQuery("update nodes set name = '' where id = -1",$link){
return $result;
});
}

function insert(& $example){
return parent::executeQuery("insert into nodes",$link) use ($example){
$id = mysql_insert_id($link);
$example->setId($id);
return $result;
});
}
}

$exampleDao = new ExampleDao();

$list = $exampleDao->getAll());

$exampleObject = $exampleDao->load(1));

$exampleDao->update($exampleObject);

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