PHP封装了一个DB数据库 mysql 的类

<?php

    // 配置数据库

 
define('DB_HOST', '127.0.0.1');   //服务器地址
define('DB_USER', 'root');   //用户名
define('DB_PASS', '');  //密码
define('DB_DATABASENAME', 'fenxiao'); //数据库
class Dbmysql
{

/*

 
*变量
**/
private $tablename=""; //表名
private $fieldname="*";
private $conn;
private $where;
private $sql;
function __construct($tablename)
{
//生成一个连接
$this->conn = mysql_connect(DB_HOST, DB_USER, DB_PASS) or die("connect failed" . mysql_error());
//选择数据库
mysql_select_db(DB_DATABASENAME, $this->conn);
//设置编码格式
mysql_query("SET NAMES utf8");
//var_dump($conn);
$this->tablename=$tablename;
}
//设置sql语句
private function setsql($sql)
{
$this->sql=$sql;
}
//设置条件语句
public function where($where)
{
$this->where=" where ".$where;
return $this;
}
//按指定字段
public function field($keyword)
{
$this->fieldname=$keyword;
return $this;
}
//设置连接查询表
public function table($table1,$table2,$field,$bool)
{
$this->tablename="$table1 LEFT JOIN $table2 ON $table1.$field$bool$table2.$field";
//print_r($this->tablename);
return $this;
}
//设置多表查询
public function addtable($table1,$table2,$field,$bool)
{
$this->tablename.=" LEFT JOIN $table2 ON $table1.$field$bool$table2.$field";
//print_r($this->tablename);
return $this;
}
//设置连接查询表
SELECT * FROM 【wx_order LEFT JOIN wx_shopcar ON wx_shopcar.oid=wx_order.oid and wx_order.uid=wx_shopcar.uid LEFT JOIN wx_goods ON wx_shopcar.gid=wx_goods.gid】 WHERE wx_order.oid=1 and wx_order.uid=3
public function settable($sql)
{
$this->tablename=$sql;
//print_r($this->tablename);
return $this;
}
//查询所有数据库 以数组形式输出
public function select()
{

/**

 

查询数据库中所有的数据
**/
$arr=array();
//执行sql语句
$result = mysql_query("select ".$this->fieldname." from ".$this->tablename.$this->where, $this->conn);


while ($row = mysql_fetch_assoc($result)) {
array_push($arr, $row);
}
return $arr;
}
//搜索指定字段数据
public function find()
{
//执行sql语句
$result = mysql_query("select ".$this->fieldname." from ".$this->tablename.$this->where, $this->conn);
$result = mysql_fetch_assoc($result);
return $result;
}
//增加数据到数据库
public function add($data)
{
$keysql='';
$valuesql='';
foreach ($data as $key => $value) {
$keysql.=",$key";
$valuesql.=",'$value'";
}
$keysql=substr($keysql, 1);
$valuesql=substr($valuesql, 1);
$result=mysql_query("insert into &quot;.$this-&gt;tablename.&quot; ($keysql) VALUES($valuesql)");
$id=mysql_insert_id();
//print_r("insert into &quot;.$this-&gt;tablename.&quot; ($keysql) VALUES($valuesql)");
return $id;
}
//修改数据库的内容
public function save($data)
{
$keysql='';
$valuesql='';
foreach ($data as $key => $value) {
$keysql.=",$key='$value'";
}
$keysql=substr($keysql, 1);
//print_r($keysql);
//echo "<br>";
$result=mysql_query("UPDATE &quot;.$this-&gt;tablename.&quot; SET ".$keysql.$this->where);
//print_r("UPDATE &quot;.$this-&gt;tablename.&quot; SET ".$keysql.$this->where);
return $result;
}
删除数据
public function delete()
{
$result=mysql_query("DELETE FROM $this->tablename $this->where");
//print_r("DELETE FROM $this->tablename $this->where");
return $result;
}
}
/**

mysql_fetch_row: 返回单列的各字段 [0]=>"111"

mysql_fetch_field: 取得字段信息。[0]=>   ['name']=>   object

mysql_fetch_array    返回数组资料。 [0]=>"asasds"   ['name']=>


*/
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