单列中的多行更新

Question

编辑进一步了解该问题。

我想从数据库中检索数据并更新单个列。

column1 | column2 | column3 
value1 | value1 | ------- 
value2 | value2 | ------- <=== this column3 rows does not have value in database yet so it will be blank when I retrieved the data 

现在我想更新column3行通过将值放到它并使用列3行中的新值发送回数据库。

我现在正在使用的当前代码现在只能检索并更新一个单独的ID，并且我卡在这里。我想要发生的是检索多个ID's并使用不同的值更新所有ID's的同一列。

这里是我使用的检索的数据的代码的一个样本，

$(document).ready(function(){ 
     $("#RetrieveList").on('click',function() { 
      var status = $('#status').val(); 
      var date = $('#Date').val(); 
      var date1 = $('#Date1').val(); 
      $.post('retrieve.php',{status:status, date:date, date1:date1}, function(data){ 
      $("#results").html(data); 
      }); 
      return false; 
     }); 

这是PHP代码，

<?php 
$servername = "localhost"; 
$username = "root"; 
$password = ""; 
$dbname = "sample_db"; 

// check data before use it and convert from string to expected type, use try, not like here: 
$date = $_POST['date']; 
$date1 = $_POST['date1']; 
// use valid data to select rows 
try { 
    //1. connect to MySQL database 
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password); 

    //2. set the PDO error mode to exception 
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 

    //3. create query string (here is answer on your question) 
    $sql = 'SELECT column1, column2, column3 FROM sample_table WHERE scheduled_start_date BETWEEN :d1 AND :d2'; 

    //4. prepare statement from query string 
    $stmt = $conn->prepare($sql); 

    //5. bind optional parameters 
    //if ($status != 'All') $stmt->bindParam(':st', $status); 

    //6. bind parameters 
    $stmt->bindParam(':d1', $date); 
    $stmt->bindParam(':d2', $date1); 

    //7. execute statement 
    $stmt->execute(); 

    //8. returns an array containing all of the result set rows 
    $result = $stmt->fetchAll(PDO::FETCH_ASSOC); 

    //get count of rows 
    $numrow = count($result); 

    //print array - there is many solution to print array, 
    //to debug you can do: 
    //print_r($result); 

} catch(PDOException $e) { 
    echo "Error: " . $e->getMessage(); 
} 
$conn = null; 

if($numrow == 0) 
    echo "No results found."; 
else 
    echo "Count: $numrow</br>"; 
{ 

echo "<table width='auto' cellpadding='1px' cellspacing='0px' border=1 align='center'> 
<tr> 
<!--<th align='center'><input id=checkall name=checkall id=checkall type=checkbox value='' /></th>--> 
<th align='center'><strong>Column1</strong></th> 
<th align='center'><strong>Column2</strong></th> 
<th align='center'><strong>Column3</strong></th> 
</tr>"; 

foreach ($result as $row => $info) { 
echo "<form action='crqretrieve_status.php' method='post'>"; 
echo"<tr>"; 
echo "<td align='center'>" . $info['column1'] . "<input type=hidden name=column1 value=" . $info['column1'] . " </td>"; 
echo "<td align='center'>" . $info['column2'] . "<input type=hidden name=column2 value=" . $info['column2'] . " </td>"; 
echo "<td align='center'>" . "<input name=column3 value='' </td>"; 
echo "</tr>"; 
echo "</form>"; 
} 
} 
echo "</table>"; 

?> 

从上面的代码，它具有name=column3 value=''，我然后要分配一个值并将其保存到数据库。

尝试搜索周围，我不知道如何case将是有用的，因为我的更新将取决于ID's。

这是我用于单个查询更新的代码，我不知道如何将它与我上面的代码关联。我将不胜感激任何帮助。

// if the 'id' variable is set in the URL, we know that we need to edit a record 
if (isset($_GET['id'])) 
{ 
// if the form's submit button is clicked, we need to process the form 
if (isset($_POST['submit'])) 
{ 
// make sure the 'id' in the URL is valid 
if (is_numeric($_POST['id'])) 
{ 
// get variables from the URL/form 
$id = $_POST['id']; 
$column1 = $_POST['column1']; 
$column2 = htmlentities($_POST['column2'], ENT_QUOTES); 
$column3 = htmlentities($_POST['column3'], ENT_QUOTES); 
$column4 = htmlentities($_POST['column4'], ENT_QUOTES); 

// check that fields are not empty 
if ($column1 == '' || $column2 == '' || $column3 == ''|| $column4 == '') 
{ 
// if they are empty, show an error message and display the form 
$error = 'ERROR: Please fill in all required fields!'; 
renderForm($column1, $column2, $column3, $column4, $error, $id); 
} 
else 
{ 
// if everything is fine, update the record in the database 
if ($stmt = $mysqli->prepare("UPDATE sample_table SET column1 = ?, column2 = ?, column3 = ?, column4 = ? 
WHERE id=?")) 
{ 
$stmt->bind_param("ssssi", $column1, $column2, $column3, $column4, $id); 
$stmt->execute(); 
$stmt->close(); 
} 
// show an error message if the query has an error 
else 
{ 
echo "ERROR: could not prepare SQL statement."; 
} 

// redirect the user once the form is updated 
header("Location: list.php"); 
} 
} 
// if the 'id' variable is not valid, show an error message 
else 
{ 
echo "Error!"; 
} 
} 
// if the form hasn't been submitted yet, get the info from the database and show the form 
else 
{ 
// make sure the 'id' value is valid 
if (is_numeric($_GET['id']) && $_GET['id'] > 0) 
{ 
// get 'id' from URL 
$id = $_GET['id']; 

// get the record from the database 
if($stmt = $mysqli->prepare("SELECT column1, column2, column3, column4 FROM sample_table WHERE id=?")) 
{ 
$stmt->bind_param("i", $id); 
$stmt->execute(); 

$stmt->bind_result($column1, $column2, $column3, $column4); 
$stmt->fetch(); 

// show the form 
renderForm($column1, $column2, $column3, $column4, NULL, $id); 

$stmt->close(); 
} 
// show an error if the query has an error 
else 
{ 
echo "Error: could not prepare SQL statement"; 
} 
} 
// if the 'id' value is not valid, redirect the user back to the view.php page 
else 
{ 
header("Location: list.php"); 
} 
} 
} 

// close the mysqli connection 
$mysqli->close(); 

Answer 1

有几种方法做你想做的事：

一行在时间

您可以一次更新一行。您可以像您一样准备查询一次，但几次调用​​方法，始终使用不同的值。该代码看起来类似的东西：

$column1Values = array(); 
$column1Values[42] = "abc"; // key is the id in the database 
$column1Values[306] = "def"; 
// ... 

$column2Values = array(); 
$column2Values[42] = "ghi"; 
$column2Values[306] = "jkl"; 
// ... 

if ($stmt = $mysqli->prepare("UPDATE sample_table SET column1 = ?, column2 = ? WHERE id=?")) 
{ 
    $stmt->bind_param("ssi", $column1, $column2, $id); 
    for ($i=0; $i<count($column1Values); $i++) { 
     $column1 = $column1Values[$ids[$i]]; 
     $column2 = $column2Values[$ids[$i]]; 
     $id = $ids[$i]; 
     $stmt->execute(); 
    } 
    $stmt->close(); 
} 

一个更新查询来统治他们

可以作为MySQL update case help描述打造超级查询。然而，动态构建这样的SQL查询可能非常困难，更不用说您必须自己处理SQL注入。