Yaf框架封装的MySQL数据库操作示例

class Db_Mysql
{
private $_options = array();
private $db;
private $statement;
private $_fetchMode = 2;
/**
* 构造函数
*
* @param string $host
* @param string $username
* @param string $password
* @param string $dbname
* @param string $charset
*/
private function __construct($host, $username, $password, $dbname, $charset)
{
//初始化数据连接
try {
$dns = 'mysql:dbname=' . $dbname . ';host=' . $host;
$this- db = new PDO($dns, $username, $password, array(PDO::ATTR_PERSISTENT =  true, PDO::ATTR_AUTOCOMMIT =  1));
$this- db- query('SET NAMES ' . $charset);
} catch (PDOException $e) {
echo header("Content-type: text/html; charset=utf-8");
echo '<pre / ';
echo '<b Connection failed:</b ' . $e- getMessage();
die;
}
}
/**
* 调用初始化MYSQL连接
*
* @param string $config
* @return Aomp_Db_Mysql
*/
static public function getInstance($config = '')
{
$host = $config- host;
$username = $config- username;
$password = $config- password;
$dbname = $config- dbname;
$charset = $config- charset;
$db = new self($host, $username, $password, $dbname, $charset);
return $db;
}
/**
* 获取多条数据
*
* @param string $sql
* @param array $bind
* @param string $fetchMode
* @return multitype:
*/
public function fetchAll($sql, $bind = array(), $fetchMode = null)
{
if($fetchMode === NULL){
$fetchMode = $this- _fetchMode;
}
$stmt = $this- query($sql, $bind);
$res = $stmt- fetchAll($fetchMode);
return $res;
}
/**
* 获取单条数据
*
* @param string $sql
* @param array $bind
* @param string $fetchMode
* @return mixed
*/
public function fetchRow($sql, array $bind = array(), $fetchMode = null)
{
if ($fetchMode === null) {
$fetchMode = $this- _fetchMode;
}
$stmt = $this- query($sql, $bind);
$result = $stmt- fetch($fetchMode);
return $result;
}
/**
* 获取统计或者ID
*
* @param string $sql
* @param array $bind
* @return string
*/
public function fetchOne($sql, array $bind = array())
{
$stmt = $this- query($sql, $bind);
$res = $stmt- fetchColumn(0);
return $res;
}
/**
* 增加
*
* @param string $table
* @param array $bind
* @return number
*/
public function insert($table, array $bind)
{
$cols = array();
$vals = array();
foreach ($bind as $k =  $v) {
$cols[] = '`' . $k . '`';
$vals[] = ':' . $k;
unset($bind[$k]);
$bind[':' . $k] = $v;
}
$sql = 'INSERT INTO '
. $table
. ' (' . implode(',', $cols) . ') '
. 'VALUES (' . implode(',', $vals) . ')';
$stmt = $this- query($sql, $bind);
$res = $stmt- rowCount();
return $res;
}
/**
* 删除
*
* @param string $table
* @param string $where
* @return boolean
*/
public function delete($table, $where = '')
{
$where = $this- _whereExpr($where);
$sql = 'DELETE FROM '
. $table
. ($where ? ' WHERE ' .$where : '');
$stmt = $this- query($sql);
$res = $stmt- rowCount();
return $res;
}
/**
* 修改
*
* @param string $table
* @param array $bind
* @param string $where
* @return boolean
*/
public function update($table, array $bind, $where = '')
{
$set = array();
foreach ($bind as $k =  $v) {
$bind[':' . $k] = $v;
$v = ':' . $k;
$set[] = $k . ' = ' . $v;
unset($bind[$k]);
}
$where = $this- _whereExpr($where);
$sql = 'UPDATE '
. $table
. ' SET ' . implode(',', $set)
. (($where) ? ' WHERE ' . $where : '');
$stmt = $this- query($sql, $bind);
$res = $stmt- rowCount();
return $res;
}
/**
* 获取新增ID
*
* @param string $tableName
* @param string $primaryKey
* @return string
*/
public function lastInsertId()
{
return (string) $this- db- lastInsertId();
}
public function query($sql, $bind = array())
{
if(!is_array($bind)){
$bind = array($bind);
}
$stmt = $this- prepare($sql);
$stmt- execute($bind);
$stmt- setFetchMode($this- _fetchMode);
return $stmt;
}
public function prepare($sql = '')
{
if(empty($sql)){
return false;
}
$this- statement = $this- db- prepare($sql);
return $this- statement;
}
public function execute($param = '')
{
if(is_array($param)){
try {
return $this- statement- execute($param);
} catch (Exception $e) {
return $e- getMessage();
}
}else {
try {
return $this- statement- execute();
} catch (Exception $e) {
return $e- getMessage();
}
}
}
/**
*
* @param string $where
* @return null|string
*/
protected function _whereExpr($where)
{
if(empty($where)){
return $where;
}
if(!is_array($where)){
$where = array($where);
}
$where = implode(' AND ', $where);
return $where;
}
/**
* 关闭数据库操作
*/
public function close()
{
$this- _db = null;
}
}

db.type = 'mysql'
db.host = '127.0.0.1'
db.username = 'root'
db.password = '123456'
db.dbname = 'test'
db.charset = 'UTF8'

class TestController extends Yaf_Controller_Abstract
{
public function indexAction()
{
$config = Yaf_Application::app()- getConfig()- db;
$db = Db_Mysql::getInstance($config);
$row = $db- fetchOne('select count(*) from `user`');
print_r($row);die;
}
}