dsn = 'mysql:host=' . $dbhost . ';dbname=' . $dbname; $this->dbh = new pdo($this->dsn, $dbuser, $dbpasswd); $this->dbh->exec('set character_set_connection=' . $dbcharset . ', character_set_results=' . $dbcharset . ', character_set_client=binary'); } catch(pdoexception $e) { $this->outputerror($e->getmessage()); } } /** * 防止克隆 * */ private function __clone() { } /** * singleton instance * * @return object */ public static function getinstance($dbhost, $dbuser, $dbpasswd, $dbname, $dbcharset) { if (self::$_instance === null) { self::$_instance = new self($dbhost, $dbuser, $dbpasswd, $dbname, $dbcharset); } return self::$_instance; } /** * query 查询 * * @param string $strsql sql语句 * @param string $querymode 查询方式(all or row) * @param boolean $debug * @return array */ public function query($strsql, $querymode = 'all', $debug = false) { if ($debug === true) $this->debug($strsql); $recordset = $this->dbh->query($strsql); $this->getpdoerror(); if ($recordset) { $recordset->setfetchmode(pdo::fetch_assoc); if ($querymode == 'all') { $result = $recordset->fetchall(); } elseif ($querymode == 'row') { $result = $recordset->fetch(); } } else { $result = null; } return $result; } /** * update 更新 * * @param string $table 表名 * @param array $arraydatavalue 字段与值 * @param string $where 条件 * @param boolean $debug * @return int */ public function update($table, $arraydatavalue, $where = '', $debug = false) { $this->checkfields($table, $arraydatavalue); if ($where) { $strsql = ''; foreach ($arraydatavalue as $key => $value) { $strsql.= , `$key`='$value'; } $strsql = substr($strsql, 1); $strsql = update `$table` set $strsql where $where; } else { $strsql = replace into `$table` (` . implode('`,`', array_keys($arraydatavalue)) . `) values (' . implode(',', $arraydatavalue) . '); } if ($debug === true) $this->debug($strsql); $result = $this->dbh->exec($strsql); $this->getpdoerror(); return $result; } /** * insert 插入 * * @param string $table 表名 * @param array $arraydatavalue 字段与值 * @param boolean $debug * @return int */ public function insert($table, $arraydatavalue, $debug = false) { $this->checkfields($table, $arraydatavalue); $strsql = insert into `$table` (` . implode('`,`', array_keys($arraydatavalue)) . `) values (' . implode(',', $arraydatavalue) . '); if ($debug === true) $this->debug($strsql); $result = $this->dbh->exec($strsql); $this->getpdoerror(); return $result; } /** * replace 覆盖方式插入 * * @param string $table 表名 * @param array $arraydatavalue 字段与值 * @param boolean $debug * @return int */ public function replace($table, $arraydatavalue, $debug = false) { $this->checkfields($table, $arraydatavalue); $strsql = replace into `$table`(` . implode('`,`', array_keys($arraydatavalue)) . `) values (' . implode(',', $arraydatavalue) . '); if ($debug === true) $this->debug($strsql); $result = $this->dbh->exec($strsql); $this->getpdoerror(); return $result; } /** * delete 删除 * * @param string $table 表名 * @param string $where 条件 * @param boolean $debug * @return int */ public function delete($table, $where = '', $debug = false) { if ($where == '') { $this->outputerror('where' is null); } else { $strsql = delete from `$table` where $where; if ($debug === true) $this->debug($strsql); $result = $this->dbh->exec($strsql); $this->getpdoerror(); return $result; } } /** * execsql 执行sql语句 * * @param string $strsql * @param boolean $debug * @return int */ public function execsql($strsql, $debug = false) { if ($debug === true) $this->debug($strsql); $result = $this->dbh->exec($strsql); $this->getpdoerror(); return $result; } /** * 获取字段最大值 * * @param string $table 表名 * @param string $field_name 字段名 * @param string $where 条件 */ public function getmaxvalue($table, $field_name, $where = '', $debug = false) { $strsql = select max( . $field_name . ) as max_value from $table; if ($where != '') $strsql.= where $where; if ($debug === true) $this->debug($strsql); $arrtemp = $this->query($strsql, 'row'); $maxvalue = $arrtemp[max_value]; if ($maxvalue == || $maxvalue == null) { $maxvalue = 0; } return $maxvalue; } /** * 获取指定列的数量 * * @param string $table * @param string $field_name * @param string $where * @param bool $debug * @return int */ public function getcount($table, $field_name, $where = '', $debug = false) { $strsql = select count($field_name) as num from $table; if ($where != '') $strsql.= where $where; if ($debug === true) $this->debug($strsql); $arrtemp = $this->query($strsql, 'row'); return $arrtemp['num']; } /** * 获取表引擎 * * @param string $dbname 库名 * @param string $tablename 表名 * @param boolean $debug * @return string */ public function gettableengine($dbname, $tablename) { $strsql = show table status from $dbname where name=' . $tablename . '; $arraytableinfo = $this->query($strsql); $this->getpdoerror(); return $arraytableinfo[0]['engine']; } /** * begintransaction 事务开始 */ private function begintransaction() { $this->dbh->begintransaction(); } /** * commit 事务提交 */ private function commit() { $this->dbh->commit(); } /** * rollback 事务回滚 */ private function rollback() { $this->dbh->rollback(); } /** * transaction 通过事务处理多条sql语句 * 调用前需通过gettableengine判断表引擎是否支持事务 * * @param array $arraysql * @return boolean */ public function exectransaction($arraysql) { $retval = 1; $this->begintransaction(); foreach ($arraysql as $strsql) { if ($this->execsql($strsql) == 0) $retval = 0; } if ($retval == 0) { $this->rollback(); return false; } else { $this->commit(); return true; } } /** * checkfields 检查指定字段是否在指定数据表中存在 * * @param string $table * @param array $arrayfield */ private function checkfields($table, $arrayfields) { $fields = $this->getfields($table); foreach ($arrayfields as $key => $value) { if (!in_array($key, $fields)) { $this->outputerror(unknown column `$key` in field list.); } } } /** * getfields 获取指定数据表中的全部字段名 * * @param string $table 表名 * @return array */ private function getfields($table) { $fields = array(); $recordset = $this->dbh->query(show columns from $table); $this->getpdoerror(); $recordset->setfetchmode(pdo::fetch_assoc); $result = $recordset->fetchall(); foreach ($result as $rows) { $fields[] = $rows['field']; } return $fields; } /** * getpdoerror 捕获pdo错误信息 */ private function getpdoerror() { if ($this->dbh->errorcode() != '00000') { $arrayerror = $this->dbh->errorinfo(); $this->outputerror($arrayerror[2]); } } /** * debug * * @param mixed $debuginfo */ private function debug($debuginfo) { var_dump($debuginfo); exit(); } /** * 输出错误信息 * * @param string $strerrmsg */ private function outputerror($strerrmsg) { throw new exception('mysql error: ' . $strerrmsg); } /** * destruct 关闭数据库连接 */ public function destruct() { $this->dbh = null; }}
调用方法:
destruct();
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