The content shared in this article is that the PHP database is based on the PDO operation class (mysql). Now I share it with everyone. Friends in need can refer to the content of this article
<?phpclass Mysql { protected static $_dbh = null; //静态属性,所有数据库实例共用,避免重复连接数据库
protected $_dbType = 'mysql'; protected $_pconnect = true; //是否使用长连接
protected $_host = 'localhost'; protected $_port = 3306; protected $_user = 'root'; protected $_pass = ''; protected $_dbName = null; //数据库名
protected $_sql = false; //最后一条sql语句
protected $_where = ''; protected $_order = ''; protected $_limit = ''; protected $_field = '*'; protected $_clear = 0; //状态，0表示查询条件干净，1表示查询条件污染
protected $_trans = 0; //事务指令数
/**
* 初始化类
* @param array $conf 数据库配置 */
public function __construct(array $conf) { class_exists('PDO') or die("PDO: class not exists."); $this->_host = $conf['host']; $this->_port = $conf['port']; $this->_user = $conf['user']; $this->_pass = $conf['password']; $this->_dbName = $conf['dbname']; //连接数据库
if ( is_null(self::$_dbh) ) { $this->_connect();
}
} /**
* 连接数据库的方法 */
protected function _connect() { $dsn = $this->_dbType.':host='.$this->_host.';port='.$this->_port.';dbname='.$this->_dbName; //持久化连接
$options = $this->_pconnect ? array(PDO::ATTR_PERSISTENT=>true) : array(); try {
$dbh = new PDO($dsn, $this->_user, $this->_pass, $options); $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); //设置如果sql语句执行错误则抛出异常，事务会自动回滚
$dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); //禁用prepared statements的仿真效果(防SQL注入)
} catch (PDOException $e) {
die('Connection failed: ' . $e->getMessage());
} $dbh->exec('SET NAMES utf8');
self::$_dbh = $dbh;
} /**
* 字段和表名添加 `符号
* 保证指令中使用关键字不出错 针对mysql
* @param string $value
* @return string
*/
protected function _addChar($value) {
if ('*'==$value || false!==strpos($value,'(') || false!==strpos($value,'.') || false!==strpos($value,'`')) {
//如果包含* 或者 使用了sql方法 则不作处理
} elseif (false === strpos($value,'`') ) {
$value = '`'.trim($value).'`';
}
return $value;
} /**
* 取得数据表的字段信息
* @param string $tbName 表名
* @return array
*/
protected function _tbFields($tbName) { $sql = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME="'.$tbName.'" AND TABLE_SCHEMA="'.$this->_dbName.'"'; $stmt = self::$_dbh->prepare($sql); $stmt->execute(); $result = $stmt->fetchAll(PDO::FETCH_ASSOC); $ret = array(); foreach ($result as $key=>$value) { $ret[$value['COLUMN_NAME']] = 1;
} return $ret;
} /**
* 过滤并格式化数据表字段
* @param string $tbName 数据表名
* @param array $data POST提交数据
* @return array $newdata
*/
protected function _dataFormat($tbName,$data) { if (!is_array($data)) return array(); $table_column = $this->_tbFields($tbName); $ret=array(); foreach ($data as $key=>$val) { if (!is_scalar($val)) continue; //值不是标量则跳过
if (array_key_exists($key,$table_column)) { $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)) { // 支持在字段的值里面直接使用其它字段 ,例如 (score+1) (name) 必须包含括号
$val = $val;
} elseif (is_string($val)) {
//将字符串中的单引号（'）、双引号（"）、反斜线（\）与 NUL（NULL 字符转义
$val = '"'.addslashes($val).'"';
} $ret[$key] = $val;
}
} return $ret;
} /**
* 执行查询 主要针对 SELECT, SHOW 等指令
* @param string $sql sql指令
* @return mixed
*/
protected function _doQuery($sql='') { $this->_sql = $sql; $pdostmt = self::$_dbh->prepare($this->_sql); //prepare或者query 返回一个PDOStatement
$pdostmt->execute(); $result = $pdostmt->fetchAll(PDO::FETCH_ASSOC); return $result;
} /**
* 执行语句 针对 INSERT, UPDATE 以及DELETE,exec结果返回受影响的行数
* @param string $sql sql指令
* @return integer
*/
protected function _doExec($sql='') { $this->_sql = $sql; return self::$_dbh->exec($this->_sql);
} /**
* 执行sql语句，自动判断进行查询或者执行操作
* @param string $sql SQL指令
* @return mixed
*/
public function doSql($sql='') { $queryIps = 'INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|LOAD DATA|SELECT .* INTO|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK';
if (preg_match('/^\s*"?(' . $queryIps . ')\s+/i', $sql)) {
return $this->_doExec($sql);
} else { //查询操作
return $this->_doQuery($sql);
}
} /**
* 获取最近一次查询的sql语句
* @return String 执行的SQL
*/
public function getLastSql() {
return $this->_sql;
} /**
* 插入方法
* @param string $tbName 操作的数据表名
* @param array $data 字段-值的一维数组
* @return int 受影响的行数 */
public function insert($tbName,array $data){ $data = $this->_dataFormat($tbName,$data); if (!$data) return; $sql = "insert into ".$tbName."(".implode(',',array_keys($data)).") values(".implode(',',array_values($data)).")"; return $this->_doExec($sql);
} /**
* 删除方法
* @param string $tbName 操作的数据表名
* @return int 受影响的行数 */
public function delete($tbName) { //安全考虑,阻止全表删除
if (!trim($this->_where)) return false; $sql = "delete from ".$tbName." ".$this->_where; $this->_clear = 1; $this->_clear(); return $this->_doExec($sql);
} /**
* 更新函数
* @param string $tbName 操作的数据表名
* @param array $data 参数数组
* @return int 受影响的行数 */
public function update($tbName,array $data) { //安全考虑,阻止全表更新
if (!trim($this->_where)) return false; $data = $this->_dataFormat($tbName,$data); if (!$data) return; $valArr = ''; foreach($data as $k=>$v){ $valArr[] = $k.'='.$v;
} $valStr = implode(',', $valArr); $sql = "update ".trim($tbName)." set ".trim($valStr)." ".trim($this->_where); return $this->_doExec($sql);
} /**
* 查询函数
* @param string $tbName 操作的数据表名
* @return array 结果集 */
public function select($tbName='') { $sql = "select ".trim($this->_field)." from ".$tbName." ".trim($this->_where)." ".trim($this->_order)." ".trim($this->_limit); //echo $sql;
$this->_clear = 1; $this->_clear(); return $this->_doQuery(trim($sql));
} /**
* @param mixed $option 组合条件的二维数组，例：$option['field1'] = array(1,'=>','or')
* @return $this */
public function where($option) { if ($this->_clear>0) $this->_clear(); $this->_where = ' where '; $logic = 'and'; if (is_string($option)) { $this->_where .= $option;
} elseif (is_array($option)) { foreach($option as $k=>$v) { if (is_array($v)) { $relative = isset($v[1]) ? $v[1] : '='; $logic = isset($v[2]) ? $v[2] : 'and'; $condition = ' ('.$this->_addChar($k).' '.$relative.' '.$v[0].') ';
} else { $logic = 'and'; $condition = ' ('.$this->_addChar($k).'='.$v.') ';
} $this->_where .= isset($mark) ? $logic.$condition : $condition; $mark = 1;
}
} return $this;
} /**
* 设置排序
* @param mixed $option 排序条件数组 例:array('sort'=>'desc')
* @return $this */
public function order($option) { if ($this->_clear>0) $this->_clear(); $this->_order = ' order by '; if (is_string($option)) { $this->_order .= $option;
} elseif (is_array($option)) { foreach($option as $k=>$v){ $order = $this->_addChar($k).' '.$v; $this->_order .= isset($mark) ? ','.$order : $order; $mark = 1;
}
} return $this;
} /**
* 设置查询行数及页数
* @param int $page pageSize不为空时为页数，否则为行数
* @param int $pageSize 为空则函数设定取出行数，不为空则设定取出行数及页数
* @return $this */
public function limit($page,$pageSize=null) { if ($this->_clear>0) $this->_clear(); if ($pageSize===null) { $this->_limit = "limit ".$page;
} else { $pageval = intval( ($page - 1) * $pageSize); $this->_limit = "limit ".$pageval.",".$pageSize;
} return $this;
} /**
* 设置查询字段
* @param mixed $field 字段数组
* @return $this */
public function field($field){ if ($this->_clear>0) $this->_clear(); if (is_string($field)) { $field = explode(',', $field);
} $nField = array_map(array($this,'_addChar'), $field); $this->_field = implode(',', $nField); return $this;
} /**
* 清理标记函数 */
protected function _clear() { $this->_where = ''; $this->_order = ''; $this->_limit = ''; $this->_field = '*'; $this->_clear = 0;
} /**
* 手动清理标记
* @return $this */
public function clearKey() { $this->_clear(); return $this;
} /**
* 启动事务
* @return void
*/
public function startTrans() {
//数据rollback 支持
if ($this->_trans==0) self::$_dbh->beginTransaction(); $this->_trans++;
return;
} /**
* 用于非自动提交状态下面的查询提交
* @return boolen
*/
public function commit() { $result = true; if ($this->_trans>0) {
$result = self::$_dbh->commit();
$this->_trans = 0;
}
return $result;
} /**
* 事务回滚
* @return boolen
*/
public function rollback() { $result = true; if ($this->_trans>0) { $result = self::$_dbh->rollback(); $this->_trans = 0;
} return $result;
} /**
* 关闭连接
* PHP 在脚本结束时会自动关闭连接。 */
public function close() { if (!is_null(self::$_dbh)) self::$_dbh = null;
}
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