在动态网面设计中很多都要涉及到对数据库的操作,但是有时跟据需要而改用其它后台数据库，就需要大量修改程序。这是一件枯燥、费时而且容易出错的功作。其实我们可以用PHP中的类来实现对数据库操作的封装，从而使写出的程序在很小的改动下就可以完成后台数据库的更改。
dbUsername=$username;$this->dbHost=$host;$this->dbPassword=$password;} //联接数库函数function dbConnect(){switch($this->dbID){case 1;return @mysql_connect($this->dbHost,$this->dbUsername,$this->dbPassword);case 2;//用支持SQL Server的函数case 3;//用支持ODBC的函数} }//关闭数库函数function dbClose($dataHandle){switch($this->dbID){case 1;mysql_close($dataHandle);case 2;//用支持SQL Server的函数case 3;//用支持ODBC的函数} }//执行SQL语句函数function dbQuery($dbName,$sql,$dbHandle){switch($this->dbID){case 1;return @mysql_db_query($dbName,$sql,$dbHandle);case 2;//用支持SQL Server的函数case 3;//用支持ODBC的函数} }//检索SQL返回值的当前记录函数function dbFetchrow($dataHandle,$offset=-1){switch($this->dbID){case 1;@mysql_data_seek($dataHandle,$offset);return @mysql_fetch_row($dataHandle);case 2;//用支持SQL Server的函数case 3;//用支持ODBC的函数} }//返回检索记录数函数function dbNumrows($dataHandle){switch($this->dbID){case 1;return @mysql_num_rows($dataHandle);case 2;//用支持SQL Server的函数case 3;//用支持ODBC的函数} }//返回检索列数函数function dbNumcols($dataHandle){switch($this->dbID){case 1;return @mysql_num_fields($dataHandle);case 2;//用支持SQL Server的函数case 3;//用支持ODBC的函数} }} 现把使用说明如下：
在程序中用dbInterface类生一个对象$test=new dbInterface; 设置参数 test->$dbUsername ;用户名 test->$dbPassword；密码 test->$dbHost；主机 void setParameter(string host, string username, string password); 数据库连接：dbhandle test->dbConnect(); 返回值：fasle ，数据库连接错误 >0, 数据库连接句柄 数据库关闭：void test->dbClose(dbhandle); 表操作：int test->dbQuery(string databasename, string sql，dbhandle);执行SQL语句 返回值： false， SQL执行错误 >0, SQL执行正确, 同时指向SQL返回值， 数据操作：int test->dbFetchrow(dataHandle，int offset);检索SQL返回值的当前记录，成功执行后，指针移向下一条记录 int test->dbNumrows(dataHandle); 取得SQL执行后（主要为SELECT语句）获得的记录数 int test->dbNumcols(dataHandle); 取得SQL执行后（主要为SELECT语句）获得的记录字段数 现在我们发一个例了讲解： 数据库采用MQSQL:其主机名为 "localhost",用户名为"root"和密码""。-----test setParameter("localhost","root","")；//设置数据库参数$db = $test->dbConnect();//连接数据库$Query = "SELECT name,pay FROM table ";//设置SQL语句$temp_result = $test->dbQuery("testdb",$Query,$db)；//执行数据主库操作echo "";$ls_num = $test->dbNumrows($temp_result); //取得查询结果的记录数echo $ls_num;echo "";if (ls_num>0 ){$ls_col = $test->dbNumcols($db); //取得表的列数echo $ls_col; echo "";$cate_result=$test->dbFetchrow($temp_result,0);//取得记录数的第一行$hcid=$cate_result[0];// 取得name的值$hcate=$cate_result[1];//取得pay的值echo $hcid;echo "";echo $hcate;}?>
在mysql中有一个testdb数据库及其中的表table1,表包括:name和pay两个字段
php封装一个class类实现mysql数据库的增删该查
time = $this->microtime_float(); require_once("config.db.php"); $this->connect($db_config["hostname"], $db_config["username"], $db_config["password"], $db_config["database"], $db_config["pconnect"]); $this->is_log = $db_config["log"]; if($this->is_log){ $handle = fopen($db_config["logfilepath"]."dblog.txt", "a+"); $this->handle=$handle; } } //数据库连接 public function connect($dbhost, $dbuser, $dbpw, $dbname, $pconnect = 0,$charset='utf8') { if( $pconnect==0 ) { $this->link_id = @mysql_connect($dbhost, $dbuser, $dbpw, true); if(!$this->link_id){ $this->halt("数据库连接失败"); } } else { $this->link_id = @mysql_pconnect($dbhost, $dbuser, $dbpw); if(!$this->link_id){ $this->halt("数据库持久连接失败"); } } if(!@mysql_select_db($dbname,$this->link_id)) { $this->halt('数据库选择失败'); } @mysql_query("set names ".$charset); } //查询 public function query($sql) { $this->write_log("查询 ".$sql); $query = mysql_query($sql,$this->link_id); if(!$query) $this->halt('Query Error: ' . $sql); return $query; } //获取一条记录（MYSQL_ASSOC，MYSQL_NUM，MYSQL_BOTH） public function get_one($sql,$result_type = MYSQL_ASSOC) { $query = $this->query($sql); $rt =& mysql_fetch_array($query,$result_type); $this->write_log("获取一条记录 ".$sql); return $rt; } //获取全部记录 public function get_all($sql,$result_type = MYSQL_ASSOC) { $query = $this->query($sql); $i = 0; $rt = array(); while($row =& mysql_fetch_array($query,$result_type)) { $rt[$i]=$row; $i++; } $this->write_log("获取全部记录 ".$sql); return $rt; } //插入 public function insert($table,$dataArray) { $field = ""; $value = ""; if( !is_array($dataArray) || count($dataArray)<=0) { $this->halt('没有要插入的数据'); return false; } while(list($key,$val)=each($dataArray)) { $field .="$key,"; $value .="'$val',"; } $field = substr( $field,0,-1); $value = substr( $value,0,-1); $sql = "insert into $table($field) values($value)"; $this->write_log("插入 ".$sql); if(!$this->query($sql)) return false; return true; } //更新 public function update( $table,$dataArray,$condition="") { if( !is_array($dataArray) || count($dataArray)<=0) { $this->halt('没有要更新的数据'); return false; } $value = ""; while( list($key,$val) = each($dataArray)) $value .= "$key = '$val',"; $value .= substr( $value,0,-1); $sql = "update $table set $value where 1=1 and $condition"; $this->write_log("更新 ".$sql); if(!$this->query($sql)) return false; return true; } //删除 public function delete( $table,$condition="") { if( empty($condition) ) { $this->halt('没有设置删除的条件'); return false; } $sql = "delete from $table where 1=1 and $condition"; $this->write_log("删除 ".$sql); if(!$this->query($sql)) return false; return true; } //返回结果集 public function fetch_array($query, $result_type = MYSQL_ASSOC){ $this->write_log("返回结果集"); return mysql_fetch_array($query, $result_type); } //获取记录条数 public function num_rows($results) { if(!is_bool($results)) { $num = mysql_num_rows($results); $this->write_log("获取的记录条数为".$num); return $num; } else { return 0; } } //释放结果集 public function free_result() { $void = func_get_args(); foreach($void as $query) { if(is_resource($query) && get_resource_type($query) === 'mysql result') { return mysql_free_result($query); } } $this->write_log("释放结果集"); } //获取最后插入的id public function insert_id() { $id = mysql_insert_id($this->link_id); $this->write_log("最后插入的id为".$id); return $id; } //关闭数据库连接 protected function close() { $this->write_log("已关闭数据库连接"); return @mysql_close($this->link_id); } //错误提示 private function halt($msg='') { $msg .= "\r\n".mysql_error(); $this->write_log($msg); die($msg); } //析构函数 public function __destruct() { $this->free_result(); $use_time = ($this-> microtime_float())-($this->time); $this->write_log("完成整个查询任务,所用时间为".$use_time); if($this->is_log){ fclose($this->handle); } } //写入日志文件 public function write_log($msg=''){ if($this->is_log){ $text = date("Y-m-d H:i:s")." ".$msg."\r\n"; fwrite($this->handle,$text); } } //获取毫秒数 public function microtime_float() { list($usec, $sec) = explode(" ", microtime()); return ((float)$usec + (float)$sec); }} ?>
time = $this->microtime_float(); require_once("config.db.php"); $this->connect($db_config["hostname"], $db_config["username"], $db_config["password"], $db_config["database"], $db_config["pconnect"]); $this->is_log = $db_config["log"]; if($this->is_log){ $handle = fopen($db_config["logfilepath"]."dblog.txt", "a+"); $this->handle=$handle; } } //数据库连接 public function connect($dbhost, $dbuser, $dbpw, $dbname, $pconnect = 0,$charset='utf8') { if( $pconnect==0 ) { $this->link_id = @mysql_connect($dbhost, $dbuser, $dbpw, true); if(!$this->link_id){ $this->halt("数据库连接失败"); } } else { $this->link_id = @mysql_pconnect($dbhost, $dbuser, $dbpw); if(!$this->link_id){ $this->halt("数据库持久连接失败"); } } if(!@mysql_select_db($dbname,$this->link_id)) { $this->halt('数据库选择失败'); } @mysql_query("set names ".$charset); } //查询 public function query($sql) { $this->write_log("查询 ".$sql); $query = mysql_query($sql,$this->link_id); if(!$query) $this->halt('Query Error: ' . $sql); return $query; } //获取一条记录（MYSQL_ASSOC，MYSQL_NUM，MYSQL_BOTH） public function get_one($sql,$result_type = MYSQL_ASSOC) { $query = $this->query($sql); $rt =& mysql_fetch_array($query,$result_type); $this->write_log("获取一条记录 ".$sql); return $rt; } //获取全部记录 public function get_all($sql,$result_type = MYSQL_ASSOC) { $query = $this->query($sql); $i = 0; $rt = array(); while($row =& mysql_fetch_array($query,$result_type)) { $rt[$i]=$row; $i++; } $this->write_log("获取全部记录 ".$sql); return $rt; } //插入 public function insert($table,$dataArray) { $field = ""; $value = ""; if( !is_array($dataArray) || count($dataArray)<=0) { $this->halt('没有要插入的数据'); return false; } while(list($key,$val)=each($dataArray)) { $field .="$key,"; $value .="'$val',"; } $field = substr( $field,0,-1); $value = substr( $value,0,-1); $sql = "insert into $table($field) values($value)"; $this->write_log("插入 ".$sql); if(!$this->query($sql)) return false; return true; } //更新 public function update( $table,$dataArray,$condition="") { if( !is_array($dataArray) || count($dataArray)<=0) { $this->halt('没有要更新的数据'); return false; } $value = ""; while( list($key,$val) = each($dataArray)) $value .= "$key = '$val',"; $value .= substr( $value,0,-1); $sql = "update $table set $value where 1=1 and $condition"; $this->write_log("更新 ".$sql); if(!$this->query($sql)) return false; return true; } //删除 public function delete( $table,$condition="") { if( empty($condition) ) { $this->halt('没有设置删除的条件'); return false; } $sql = "delete from $table where 1=1 and $condition"; $this->write_log("删除 ".$sql); if(!$this->query($sql)) return false; return true; } //返回结果集 public function fetch_array($query, $result_type = MYSQL_ASSOC){ $this->write_log("返回结果集"); return mysql_fetch_array($query, $result_type); } //获取记录条数 public function num_rows($results) { if(!is_bool($results)) { $num = mysql_num_rows($results); $this->write_log("获取的记录条数为".$num); return $num; } else { return 0; } } //释放结果集 public function free_result() { $void = func_get_args(); foreach($void as $query) { if(is_resource($query) && get_resource_type($query) === 'mysql result') { return mysql_free_result($query); } } $this->write_log("释放结果集"); } //获取最后插入的id public function insert_id() { $id = mysql_insert_id($this->link_id); $this->write_log("最后插入的id为".$id); return $id; } //关闭数据库连接 protected function close() { $this->write_log("已关闭数据库连接"); return @mysql_close($this->link_id); } //错误提示 private function halt($msg='') { $msg .= "\r\n".mysql_error(); $this->write_log($msg); die($msg); } //析构函数 public function __destruct() { $this->free_result(); $use_time = ($this-> microtime_float())-($this->time); $this->write_log("完成整个查询任务,所用时间为".$use_time); if($this->is_log){ fclose($this->handle); } } //写入日志文件 public function write_log($msg=''){ if($this->is_log){ $text = date("Y-m-d H:i:s")." ".$msg."\r\n"; fwrite($this->handle,$text); } } //获取毫秒数 public function microtime_float() { list($usec, $sec) = explode(" ", microtime()); return ((float)$usec + (float)$sec); }}