PHP数据库处理封装类实例

本文实例讲述了PHP数据库处理封装类。分享给大家供大家参考，具体如下：MySQL的操作相关

本文实例讲述了PHP数据库处理封装类。分享给大家供大家参考，具体如下：

MySQL的操作相关类，检查并使用了mysqli

<?php
 //sample15_12.php
 class mydb {
 private $user;
 private $pass;
 private $host;
 private $db;
 //Constructor function.
 public function __construct (){
 $num_args = func_num_args();
 if($num_args > 0){
 $args = func_get_args();
 $this->host = $args[0];
 $this->user = $args[1];
 $this->pass = $args[2];
 $this->connect();
 }
 }
 //Function to tell us if mysqli is installed.
 private function mysqliinstalled (){
 if (function_exists ("mysqli_connect")){
 return true;
 } else {
 return false;
 }
 }
 //Function to connect to the database.
 private function connect (){
 try {
 //Mysqli functionality.
 if ($this->mysqliinstalled()){
 if (!$this->db = new mysqli ($this->host,$this->user,$this->pass)){
 $exceptionstring = "Error connection to database: <br />";
 $exceptionstring .= mysqli_connect_errno() . ": " . mysqli_connect_error();
 throw new exception ($exceptionstring);
 }
 //Mysql functionality.
 } else {
 if (!$this->db = mysql_connect ($this->host,$this->user,$this->pass)){
 $exceptionstring = "Error connection to database: <br />";
 $exceptionstring .= mysql_errno() . ": " . mysql_error();
 throw new exception ($exceptionstring);
 }
 }
 } catch (exception $e) {
 echo $e->getmessage();
 }
 }
 //Function to select a database.
 public function selectdb ($thedb){
 try {
 //Mysqli functionality.
 if ($this->mysqliinstalled()){
 if (!$this->db->select_db ($thedb)){
 $exceptionstring = "Error opening database: $thedb: <br />";
 $exceptionstring .= $this->db->errno . ": " . $this->db->error;
 throw new exception ($exceptionstring);
 }
 //Mysql functionality.
 } else {
 if (!mysql_select_db ($thedb, $this->db)){
 $exceptionstring = "Error opening database: $thedb: <br />";
 $exceptionstring .= mysql_errno() . ": " . mysql_error();
 throw new exception ($exceptionstring);
 }
 }
 } catch (exception $e) {
 echo $e->getmessage();
 }
 }
 //Function to perform a query.
 public function execute ($thequery){
 try {
 //Mysqli functionality.
 if ($this->mysqliinstalled()){
 if (!$this->db->query ($thequery)){
 $exceptionstring = "Error performing query: $thequery: <br />";
 $exceptionstring .= $this->db->errno . ": " . $this->db->error;
 throw new exception ($exceptionstring);
 } else {
 echo "Query performed correctly: " . $this->db->affected_rows . " row(s) affected.<br />";
 }
 //Mysql functionality.
 } else {
 if (!mysql_query ($thequery, $this->db)){
 $exceptionstring = "Error performing query: $thequery: <br />";
 $exceptionstring .= mysql_errno() . ": " . mysql_error();
 throw new exception ($exceptionstring);
 } else {
 echo "Query performed correctly: " . mysql_affected_rows () . " row(s) affected.<br />";
 }
 }
 } catch (exception $e) {
 echo $e->getmessage();
 }
 }
 //Function to return a row set.
 public function getrows ($thequery){
 try {
 //Mysqli functionality.
 if ($this->mysqliinstalled()){
 if ($result = $this->db->query ($thequery)){
 $returnarr = array ();
 while ($adata = $result->fetch_array ()){
 $returnarr = array_merge ($returnarr,$adata);
 }
 return $returnarr;
 } else {
 $exceptionstring = "Error performing query: $thequery: <br />";
 $exceptionstring .= $this->db->errno . ": " . $this->db->error;
 throw new exception ($exceptionstring);
 }
 //Mysql functionality.
 } else {
 if (!$aquery = mysql_query ($thequery)){
 $exceptionstring = "Error performing query: $thequery: <br />";
 $exceptionstring .= mysql_errno() . ": " . mysql_error();
 throw new exception ($exceptionstring);
 } else {
 $returnarr = array ();
 while ($adata = mysql_fetch_array ($aquery)){
 $returnarr = array_merge ($returnarr,$adata);
 }
 return $returnarr;
 }
 }
 } catch (exception $e) {
 echo $e->getmessage();
 }
 }
 //Function to close the database link.
 public function __destruct() {
 try {
 //Mysqli functionality.
 if ($this->mysqliinstalled()){
 if (!$this->db->close()){
 $exceptionstring = "Error closing connection: <br />";
 $exceptionstring .= $this->db->errno . ": " . $this->db->error;
 throw new exception ($exceptionstring);
 }
 //Mysql functionality.
 } else {
 if (!mysql_close ($this->db)){
 $exceptionstring = "Error closing connection: <br />";
 $exceptionstring .= mysql_errno() . ": " . mysql_error();
 throw new exception ($exceptionstring);
 }
 }
 } catch (exception $e) {
 echo $e->getmessage();
 }
 }
 }
 //Now, let us create an instance of mydb.
 $mydb = new mydb ("localhost","root","");
 //Select a database to use.
 $mydb->selectdb ("wps");
 //Now, let's perform an action.
 //$adata = $mydb->execute ("UPDATE cd SET title='Hybrid Theory' WHERE cdid='2'");
 //Then, let's try to return a row set.
 $adata = $mydb->getrows ("SELECT * FROM wp_terms");
 for ($i = 0; $i < count ($adata); $i++){
 echo $adata[$i] . "<br />";
 }
 $mydb->selectdb("test");
 $result = $mydb->execute("UPDATE user SET age = 23 WHERE id = 2");
 echo "<br />";
 echo $result;
?>