最近升级php7发现不支持mysql扩展，需要改成用mysqli扩展

看代码class Db{

private $username = '';

private $password = '';

private $host = '';

private $db = '';

private $mysqli_conn;

public function __construct(){

$this->mysqli_conn = @mysqli_connect($this->host,$this->username, $this->password);

if(!$this->mysqli_conn){

die("could not connect to the database:\n".mysqli_error($this->mysqli_conn));

}

mysqli_query($this->mysqli_conn,"set names 'utf8'");//编码转化

$select_db = mysqli_select_db($this->mysqli_conn,$this->db);

}

public function query($query){

return mysqli_query($this->mysqli_conn, $query);

}

public function fetch_assoc($result){

return mysqli_fetch_assoc($result);

}

public function fetch_array($result){

return mysqli_fetch_array($result);

}

public function getAll($table,$filed,$where='1=1',$order='',$limit=''){

$array = array();

$sql = "SELECT {$filed} FROM {$table} WHERE {$where} {$order} {$limit}";

$result = $this->query($sql) or die("db.php;Action:getAll;problem:".$sql.mysqli_error($this->mysqli_conn));

while($row = $this->fetch_assoc($result)){

$array[] = $row;

}

return $array;

}

public function getOne($table,$filed,$where='1=1'){

$sql ="SECLECT {$filed} FROM {$table} WHERE {$where} limit 1";

$result = $this->query($sql) or die("db.php;Action:getOne;problem:".$sql.mysqli_error($this->mysqli_conn));

$row = $this->fetch_assoc($result);

return $row;

}

public function getCount($table,$where="1=1"){

$sql ="SELECT COUNT(1) as count FROM {$table} WHERE {$where}";

$result = $this->query($sql) or die("db.php;Action:getCount;".$sql.mysqli_error($this->mysqli_conn));

$row = $this->fetch_array($result);

if(!$row['count']){

$row['count'] = '0';

}

return $row['count'];

}

public function delete($table,$where="1=1"){

$sql ="DELETE FROM {$table} WHERE {$where}";

$result = $this->query($sql) or die("db.php;Action:delete;".$sql.mysqli_error($this->mysqli_conn));

return $result;

}

public function insert($table,array $data){

$data = $this->_dataFormat($data);

$sql = "insert into ".$table."(".implode(',',array_keys($data)).") values (".implode(',',array_values($data)).")";

$result = $this->query($sql) or die("db.php;Action:insert;".$sql.mysqli_error($this->mysqli_conn));

return $result;

}

public function update($table,array $data,$where="1=1") {

$data = $this->_dataFormat($data);

if (!$data) return;

$valArr = '';

foreach($data as $k=>$v){

$valArr[] = $k.'='.$v;

}

$valStr = implode(',', $valArr);

$sql = "update ".$table." set ".trim($valStr)." where {$where}";

$result = $this->query($sql) or die("db.php;Action:update;".$sql.mysqli_error($this->mysqli_conn));

return $result;

}

priavte function _dataFormat($data) {

if (!is_array($data)) return array();

$ret=array();

foreach ($data as $key=>$val) {

if (!is_scalar($val)) continue; //值不是标量则跳过

$key = $this->_addChar($key);

if (is_int($val)) {

$val = intval($val);

} elseif (is_float($val)) {

$val = floatval($val);

} elseif (preg_match('/^\(\w*(\+|\-|\*|\/)?\w*\)$/i', $val)) {

$val = $val;

} elseif (is_string($val)) {

$val = '"'.addslashes($val).'"';

}

$ret[$key] = $val;

}

return $ret;

}

priavte function _addChar($value) {

if ('*'==$value || false!==strpos($value,'(') || false!==strpos($value,'.') || false!==strpos($value,'`')) {

} elseif (false === strpos($value,'`') ) {

$value = '`'.trim($value).'`';

}

return $value;

}

}

主要注意是mysqli_query这个函数两个参数是必须填写的,而mysql_query参数与之相反和第二个参数可以不填写！