PHP封装了一个DB数据库mysql的类

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); $result=mysql_query("insert into `".$this->tablename."` ($keysql) VALUES($valuesql)"); $id=mysql_insert_id(); //print_r("insert into `".$this->tablename."` ($keysql) VALUES($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 "
"; $result=mysql_query("UPDATE `".$this->tablename."` SET ".$keysql.$this->where); //print_r("UPDATE `".$this->tablename."` SET ".$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']=> */ ?>