一、数据库查询语句
描述:去数据库的指定表中根据条件查询语句
$con=mysqli_connect('localhost','root','','librarydb'); mysqli_query($con,'set names utf8'); mysqli_query($con,'set character_set_client=utf8'); mysqli_query($con,'set character_set_results=utf8'); $sql="select * from book where bookId='1' "; $result=$con->query($sql); if($result->num_rows>0){ $info=[]; for($i=0;$row=$result->fetch_assoc();$i++){ $info[$i]=$row; } print_r($info); }
二、数据库修改语句
$con=mysqli_connect('localhost','root','','librarydb'); mysqli_query($con,'set names utf8'); mysqli_query($con,'set character_set_client=utf8'); mysqli_query($con,'set character_set_results=utf8'); $sql="update book set bookName='鲁滨逊漂流记' where bookId='123' "; $result=$con->query($sql); if($result){ echo '修改成功'; }else{ echo '修改失败,请重新修改'; }
三、数据库增加语句
$con=mysqli_connect('localhost','root','','librarydb'); if($con){ echo '连接成功Loading...'; mysqli_query($con,'set names utf8'); mysqli_query($con,'set character_set_client=utf8'); mysqli_query($con,'set character_set_results=utf8'); $sql="insert into book (bookId,bookName,bookAuthor,bookPrice,bookNum) values('3','时间科学','不知道','85','16')"; $result=$con->query($sql); if($result){ echo '添加成功'; }else{ echo '添加失败,请重新添加'; } }else{ echo '连接失败,请重连'; }
四、数据库删除语句
$con=mysqli_connect('localhost','root','','librarydb'); if($con){ echo '连接成功Loading...'; mysqli_query($con,'set names utf8'); mysqli_query($con,'set character_set_client=utf8'); mysqli_query($con,'set character_set_results=utf8'); $sql="delete from book where bookName='时间科学'"; $result=$con->query($sql); if($result){ echo '删除成功'; }else{ echo '删除失败,请重新删除'; } }else{ echo '连接失败,请重连'; }
五、html,数据库,php前后端交互
1、引入jquery框架
2、需要和后台交互的话,调用 ajax 方法
ajax方法需要一系列参数:type : 'post/get',
url : '给一个目标网址(一定要加http)',
datatype : 'json',
data : (data是post专有的){ ... },
success : function(data){
console.log(data);
}
在php中内置了两个对象用来接收前端发来的消息
$GET:用于获取在前端通过get请求发来的信息
$SET:用于获取在前端通过post请求发来的信息