利用php实现数据的增删改查

利用php实现数据的增删改查

//连接数据库
$con = mysqli_connect("localhost","username","password","database");
if(!$con){
  die("无法连接到数据库".mysqli_connect_error());
}

//插入数据
$name = $_POST['name'];
$age = $_POST['age'];
$city = $_POST['city'];

$sql = "INSERT INTO user(name,age,city) VALUES('$name','$age','$city')";

if(mysqli_query($con,$sql)){
  echo "插入成功";
}else{
  echo "插入失败".mysqli_error($con);
}

//查询数据
$sql = "SELECT * FROM user";
$result = mysqli_query($con,$sql);

if(mysqli_num_rows($result)>0){
  while($row = mysqli_fetch_assoc($result)){
    echo "姓名:".$row['name']." 年龄:".$row['age']." 城市:".$row['city']."
";
  }
}else{
  echo "暂无数据";
}

//更新数据
$id = $_POST['id'];
$name = $_POST['name'];
$age = $_POST['age'];
$city = $_POST['city'];

$sql = "UPDATE user SET name='$name',age='$age',city='$city' WHERE id=$id";

if(mysqli_query($con,$sql)){
  echo "更新成功";
}else{
  echo "更新失败".mysqli_error($con);
}

//删除数据
$id = $_POST['id'];

$sql = "DELETE FROM user WHERE id=$id";

if(mysqli_query($con,$sql)){
  echo "删除成功";
}else{
  echo "删除失败".mysqli_error($con);
}

//关闭连接
mysqli_close($con);