本文目录一览:
- 1、php封装一个class类实现mysql数据库的增删该查
- 2、php mysql与mysqli 区别
- 3、PHP访问MYSQL数据库封装类(附函数说明)
- 4、php实现mysql封装类示例
- 5、php查找MySQL中某张表的数据,如何封装为json数组?
- 6、php使用mysqli和pdo扩展,测试对比mysql数据库的执行效率完整示例
php封装一个class类实现mysql数据库的增删该查
?php
class db{
private $db;
const MYSQL_OPT_READ_TIMEOUT = 11;
const MYSQL_OPT_WRITE_TIMEOUT = 12;
private $tbl_name;
private $where;
private $sort;
private $fields;
private $limit;
public static $_instance = null;
function __construct(){
$cfg = loadConfig('db');
$db = mysqli_init();
$db-options(self::MYSQL_OPT_READ_TIMEOUT, 3);
$db-options(self::MYSQL_OPT_WRITE_TIMEOUT, 1);
@$db-real_connect($cfg['host'],$cfg['user'],$cfg['pwd'],$cfg['db']);
if ($db-connect_error) {
$this-crash($db-errno,$db-error);
}
$db-set_charset("utf8");
$this-db = $db;
//echo $this-db-stat;
}
public static function getInstance(){
if(!(self::$_instance instanceof self)){
self::$_instance = new self();
}
return self::$_instance;
}
private function __clone() {} //覆盖__clone()方法,禁止克隆
public function find($conditions = null){
if($conditions) $this-where($conditions);
return $this-getArray($this-buildSql(),1);
}
public function findAll($conditions = null){
if($conditions) $this-where($conditions);
return $this-getArray($this-buildSql());
}
//表
public function t($table){ $this-tbl_name = $table; return $this;}
//条件
public function where($conditions){
$where = '';
if(is_array($conditions)){
$join = array();
foreach( $conditions as $key = $condition ){
$condition = $this-db-real_escape_string($condition);
$join[] = "`{$key}` = '{$condition}'";
}
$where = "WHERE ".join(" AND ",$join);
}else{
if(null != $conditions) $where = "WHERE ".$conditions;
}
$this-where = $where;
return $this;
}
//排序
public function sort($sort){
if(null != $sort) $sort = "ORDER BY {$sort}";
$this-sort = $sort;
return $this;
}
//字段
public function fields($fields){ $this-fields = $fields; return $this; }
public function limit($limit){$this-limit = $limit; return $this;}
private function buildSql(){
$this-fields = empty($this-fields) ? "*" : $this-fields;
$sql = "SELECT {$this-fields} FROM {$this-tbl_name} {$this-where} {$this-sort}";
accessLog('db_access',$sql);
if(null != $this-limit)$sql .= " limit {$this-limit}";
return $sql;
}
/**
* 返回查询数据
* @param $sql
* @param bool $hasOne
* @return array|bool|mixed
*/
private function getArray($sql,$hasOne = false){
if($this-db-real_query($sql) ){
if ($result = $this-db-use_result()) {
$row = array();
if($hasOne){
$row = $result-fetch_assoc();
}else{
while($d = $result-fetch_assoc()) $row[] = $d;
}
$result-close();
$this-fields = "*";
return $row;
}else{
return false;
}
}else{
if($this-db-error){
$this-crash($this-db-errno,$this-db-error,$sql);
}
}
}
public function findSql($sql,$hasOne = false){
accessLog('db_access',$sql);
if($this-db-real_query($sql) ){
if ($result = $this-db-use_result()) {
$row = array();
if($hasOne){
$row = $result-fetch_assoc();
}else{
while($d = $result-fetch_assoc()) $row[] = $d;
}
$result-close();
$this-fields = "*";
return $row;
}else{
return false;
}
}else{
if($this-db-error){
$this-crash($this-db-errno,$this-db-error,$sql);
}
}
}
public function create($row){
if(!is_array($row))return FALSE;
$row = $this-prepera_format($row);
if(empty($row))return FALSE;
foreach($row as $key = $value){
$cols[] = '`'.$key.'`';
$vals[] = "'".$this-db-real_escape_string($value)."'";
}
$col = implode(',', $cols);
$val = implode(',', $vals);
$sql = "INSERT INTO `{$this-tbl_name}` ({$col}) VALUES ({$val})";
accessLog('db_access',$sql);
if( FALSE != $this-db-query($sql) ){ // 获取当前新增的ID
if($this-db-insert_id){
return $this-db-insert_id;
}
if($this-db-affected_rows){
return true;
}
}
return FALSE;
}
//直接执行sql
public function runSql($sql){
accessLog('db_access',$sql);
if( FALSE != $this-db-query($sql) ){ // 获取当前新增的ID
return true;
}else{
return false;
}
}
public function update($row){
$where = "";
$row = $this-prepera_format($row);
if(empty($row))return FALSE;
foreach($row as $key = $value){
$value = $this-db-real_escape_string($value);
$vals[] = "`{$key}` = '{$value}'";
}
$values = join(", ",$vals);
$sql = "UPDATE {$this-tbl_name} SET {$values} {$this-where}";
accessLog('db_access',$sql);
if( FALSE != $this-db-query($sql) ){ // 获取当前新增的ID
if( $this-db-affected_rows){
return true;
}
}
return false;
}
function delete(){
$sql = "DELETE FROM {$this-tbl_name} {$this-where}";
if( FALSE != $this-db-query($sql) ){ // 获取当前新增的ID
if( $this-db-affected_rows){
return true;
}
}
return FALSE;
}
private function prepera_format($rows){
$columns = $this-getArray("DESCRIBE {$this-tbl_name}");
$newcol = array();
foreach( $columns as $col ){
$newcol[$col['Field']] = $col['Field'];
}
return array_intersect_key($rows,$newcol);
}
//崩溃信息
private function crash($number,$message,$sql=''){
$msg = 'Db Error '.$number.':'.$message ;
if(empty($sql)){
echo t('db_crash');
}else{
$msg .= " SQL:".$sql;
echo t('db_query_err');
}
accessLog('db_error',$msg);
exit;
}
}
php mysql与mysqli 区别
1、mysql是非持继连接函数,mysql每次链接都会打开一个连接的进程。
2、mysqli是永远连接函数,mysqli多次运行mysqli将使用同一连接进程,从而减少了服务器的开销。mysqli封装了诸如事务等一些高级操作,同时封装了DB操作过程中的很多可用的方法。
mysqli连接是永久连接,而mysql是非永久连接。
mysql连接:每当第二次使用的时候,都会重新打开一个新的进程。
mysqli连接:一直都只使用同一个进程。
PHP访问MYSQL数据库封装类(附函数说明)
复制代码
代码如下:
?php
/*
MYSQL
数据库访问封装类
MYSQL
数据访问方式,php4支持以mysql_开头的过程访问方式,php5开始支持以mysqli_开头的过程和mysqli面向对象
访问方式,本封装类以mysql_封装
数据访问的一般流程:
1,连接数据库
mysql_connect
or
mysql_pconnect
2,选择数据库
mysql_select_db
3,执行SQL查询
mysql_query
4,处理返回的数据
mysql_fetch_array
mysql_num_rows
mysql_fetch_assoc
mysql_fetch_row
etc
*/
class
db_mysql
{
var
$querynum
=
;
//当前页面进程查询数据库的次数
var
$dblink
;
//数据库连接资源
//链接数据库
function
connect($dbhost,$dbuser,$dbpw,$dbname='',$dbcharset='utf-8',$pconnect=0
,
$halt=true)
{
$func
=
empty($pconnect)
?
'mysql_connect'
:
'mysql_pconnect'
;
$this-dblink
=
@$func($dbhost,$dbuser,$dbpw)
;
if
($halt
!$this-dblink)
{
$this-halt("无法链接数据库!");
}
//设置查询字符集
mysql_query("SET
character_set_connection={$dbcharset},character_set_results={$dbcharset},character_set_client=binary",$this-dblink)
;
//选择数据库
$dbname
@mysql_select_db($dbname,$this-dblink)
;
}
//选择数据库
function
select_db($dbname)
{
return
mysql_select_db($dbname,$this-dblink);
}
//执行SQL查询
function
query($sql)
{
$this-querynum++
;
return
mysql_query($sql,$this-dblink)
;
}
//返回最近一次与连接句柄关联的INSERT,UPDATE
或DELETE
查询所影响的记录行数
function
affected_rows()
{
return
mysql_affected_rows($this-dblink)
;
}
//取得结果集中行的数目,只对select查询的结果集有效
function
num_rows($result)
{
return
mysql_num_rows($result)
;
}
//获得单格的查询结果
function
result($result,$row=0)
{
return
mysql_result($result,$row)
;
}
//取得上一步
INSERT
操作产生的
ID,只对表有AUTO_INCREMENT
ID的操作有效
function
insert_id()
{
return
($id
=
mysql_insert_id($this-dblink))
=
?
$id
:
$this-result($this-query("SELECT
last_insert_id()"),
0);
}
//从结果集提取当前行,以数字为key表示的关联数组形式返回
function
fetch_row($result)
{
return
mysql_fetch_row($result)
;
}
//从结果集提取当前行,以字段名为key表示的关联数组形式返回
function
fetch_assoc($result)
{
return
mysql_fetch_assoc($result);
}
//从结果集提取当前行,以字段名和数字为key表示的关联数组形式返回
function
fetch_array($result)
{
return
mysql_fetch_array($result);
}
//关闭链接
function
close()
{
return
mysql_close($this-dblink)
;
}
//输出简单的错误html提示信息并终止程序
function
halt($msg)
{
$message
=
"html\nhead\n"
;
$message
.=
"meta
content='text/html;charset=gb2312'\n"
;
$message
.=
"/head\n"
;
$message
.=
"body\n"
;
$message
.=
"数据库出错:".htmlspecialchars($msg)."\n"
;
$message
.=
"/body\n"
;
$message
.=
"/html"
;
echo
$message
;
exit
;
}
}
?
php实现mysql封装类示例
php封装mysql类
复制代码
代码如下:
?php
class
Mysql
{
private
$host;
private
$user;
private
$pwd;
private
$dbName;
private
$charset;
private
$conn
=
null;
public
function
__construct()
{
$this-host
=
'localhost';
$this-user
=
'root';
$this-pwd
=
'root';
$this-dbName
=
'test';
$this-connect($this-host,$this-user,$this-pwd);
$this-switchDb($this-dbName);
$this-setChar($this-charset);
}
//负责链接
private
function
connect($h,$u,$p)
{
$conn
=
mysql_connect($h,$u,$p);
$this-conn
=
$conn;
}
//负责切换数据库
public
function
switchDb($db)
{
$sql
=
'use'
.
$db;
$this-query($sql);
}
//负责设置字符集
public
function
setChar($char)
{
$sql
=
'set
names'
.
$char;
$this-query($sql);
}
//负责发送sql查询
public
function
query($sql)
{
return
mysql_query($sql,$this-conn);
}
//负责获取多行多列的select结果
public
function
getAll($sql)
{
$list
=
array();
$rs
=
$this-query($sql);
if
(!$rs)
{
return
false;
}
while
($row
=
mysql_fetch_assoc($rs))
{
$list[]
=
$row;
}
return
$list;
}
public
function
getRow($sql)
{
$rs
=
$this-query($sql);
if(!$rs)
{
return
false;
}
return
mysql_fetch_assoc($rs);
}
public
function
getOne($sql)
{
$rs
=
$this-query($sql);
if
(!$rs)
{
return
false;
}
return
mysql_fetch_assoc($rs);
return
$row[0];
}
public
function
close()
{
mysql_close($this-conn);
}
}
echo
'pre';
$mysql
=
new
Mysql();
print_r($mysql);
$sql
=
"insert
into
stu
values
(4,'wangwu','99998')";
if($mysql-query($sql)){
echo
"query成功";
}else
{
echo
"失败";
}
echo
"br
/";
$sql
=
"select
*
from
stu";
$arr
=
$mysql-getAll($sql);
print_r($arr);
?
php查找MySQL中某张表的数据,如何封装为json数组?
$sql
=
"SELECT*
FROM
table1
";//查询表table1
$result
=
mysqli_query($conn,$sql);//将表与数据库连接
$output
=
[];
//用于盛放查询到的商品
while(($row=mysqli_fetch_assoc($result))!==null){
$output[]
=
$row;
}
echo
json_encode($output);//输出查询到的数据
php使用mysqli和pdo扩展,测试对比mysql数据库的执行效率完整示例
本文实例讲述了php使用mysqli和pdo扩展,测试对比mysql数据库的执行效率。分享给大家供大家参考,具体如下:
?php
/**
*
测试pdo和mysqli的执行效率
*/
header("Content-type:text/html;charset=utf-8");
//通过pdo链接数据库
$pdo_startTime
=
microtime(true);
$pdo
=
new
PDO("mysql:host=localhost;dbname=test","root","1234",array(PDO::MYSQL_ATTR_INIT_COMMAND
=
"SET
NAMES'utf8';"));
for($i=1;$i=100;$i++){
$title
=
"pdo标题".$i;
$content
=
"pdo内容".$i;
$addtime
=
time();
$user_id
=
$i;
$pdo_sql
=
"INSERT
INTO
`article`(`title`,`content`,`addtime`,`user_id`)
VALUES(:title,:content,:addtime,:user_id)";
$sth
=
$pdo-prepare($pdo_sql);
$sth-bindParam(':title',$title);
$sth-bindParam(':content',$content);
$sth-bindParam(':addtime',$addtime);
$sth-bindParam(':user_id',$user_id);
$sth-execute();
}
$pdo_endTime
=
microtime(true);
$pdo_time
=
$pdo_endTime
-
$pdo_startTime;
echo
$pdo_time;
echo
"hr/";
//通过mysql链接数据库
$mysqli_startTime
=
microtime(true);
$mysqli
=
mysqli_connect("localhost","root","1234","test")
or
die("数据连接失败");
mysqli_query($mysqli,"set
names
utf8");
for($i=1;$i=100;$i++){
$title
=
"mysqli标题".$i;
$content
=
"mysqli内容".$i;
$addtime
=
time();
$user_id
=
$i;
$sql
=
"INSERT
INTO
`article`(`title`,`content`,`addtime`,`user_id`)
VALUES('".$title."','".$content."',".$addtime.",".$user_id.")";
mysqli_query($mysqli,$sql);
}
$mysqli_endTime
=
microtime(true);
$mysqli_time
=
$mysqli_endTime
-
$mysqli_startTime;
echo
$mysqli_time;
echo
"hr/";
if($pdo_time
$mysqli_time){
echo
"pdo的执行时间是mysqli的".round($pdo_time/$mysqli_time)."倍";
}else{
echo
"mysqli的执行时间是pdo的".round($mysqli_time/$pdo_time)."倍";
}
测试结果:其实经过多次测试,pdo和mysqli的执行效率差不多。
更多关于PHP相关内容感兴趣的读者可查看本站专题:《PHP基于pdo操作数据库技巧总结》、《php+mysqli数据库程序设计技巧总结》、《php面向对象程序设计入门教程》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》
希望本文所述对大家PHP程序设计有所帮助。
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