Day6 职训(机器学习与资料分析工程师培训班): PHP连接SQL

上午: Python程序设计

延续昨日课程，今日从流程控制开始，课程中老师也有出几个练习题让同学试着自己coding，都算满简单的练习 Python流程控制:

1. 文字输入&输出: input, output
2. 判断式 if & else & elif . 进阶→List Comprehension
3. while回圈 & break & continue
4. for回圈

下午: 人工智慧与机器学习概论

今天老师教学如何透过php连结SQL，将资料写入DB或是从DB读取资料:

写入DB

<?php 
//step 1: connect db 
 if (!empty($_GET['value'])) {
    $myvalue=$_GET['value'];
} else{
	$myvalue=NULL;
}

$mysqli = new mysqli("localhost","test123","test123","aiotdb");

// Check connection
if ($mysqli -> connect_errno) {
  echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
  exit();
} else {
	print "Success! " ;
}

//step 2: sql query
if ($myvalue!=NULL){
if ($result = $mysqli -> query("insert into sensors (value) values ($myvalue)")) {
  echo "New value ". $myvalue  ." has been added.: "  ;
}else{
	echo "nothing added!";
}
}
//step 3: disconnect db
$mysqli -> close();

?>

将DB资料转成JSON

<?php 
//step 1: connect db 

$mysqli = new mysqli("localhost","test123","test123","aiotdb");

// Check connection
if ($mysqli -> connect_errno) {
  echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
  exit();
} 

//step 2: sql query

if ($result = $mysqli -> query("select * from sensors")) {

}

//step 3: fetch array from $result
$data=[];
$index= 0;
while($row = $result -> fetch_array(MYSQLI_NUM)){
$data[$index]=$row;
$index=$index+1;
}
//step 4: ecode json
echo json_encode($data);
//step 5: disconnect db
$mysqli -> close();

?>