在PHP中编写数据库的属性

Question

我正在编写一个应用程序，用户可以在其中输入数据库名称，我应该使用PHP将所有内容写入表中。我可以在知道数据库名称下面的代码。

$result = mysqli_query($con,"SELECT * FROM course"); 

echo "<table border='1'> 
<tr> 
<th>blablabla</th> 
<th>blabla</th> 
<th>blablabla</th> 
<th>bla</th> 
</tr>"; 

while($row = mysqli_fetch_array($result)) 
    { 
    echo "<tr>"; 
    echo "<td>" . $row['blablabla'] . "</td>"; 
    echo "<td>" . $row['blabla'] . "</td>"; 
    echo "<td>" . $row['blablabla'] . "</td>"; 
    echo "<td>" . $row['bla'] . "</td>"; 
    echo "</tr>"; 
    } 
echo "</table>"; 

在这个例子中，我可以告诉它，因为我知道表的名称当然，它有4 attributes.But我希望能够显示结果，无论这个名字的用户entered.So如果用户想要查看教师的内容应该有两列，而不是4.我可以如何完成这一点。我用html获取表名。

Table:<input type="text" name="table"> 

编辑：丹尼斯的回答和GrumpyCroutons的回答都是correct.You也可以问我，如果你不明白在他们的解决方案的东西。

Answer 1

快速写下来，评论它（这样你可以很容易地知道发生了什么，你看到），并为你测试它。

<form method="GET"> 
     <input type="text" name="table"> 
    </form> 

    <?php 


    //can be done elsewhere, I used this for testing. vv 
    $config = array(
     'SQL-Host' => '', 
     'SQL-User' => '', 
     'SQL-Pass' => '', 
     'SQL-Database' => '' 
    ); 
    $con = mysqli_connect($config['SQL-Host'], $config['SQL-User'], $config['SQL-Pass'], $config['SQL-Database']) or die("Error " . mysqli_error($con)); 
    //can be done elsewhere, I used this for testing. ^^ 


    if(!isSet($_GET['table'])) { //check if table choser form was submitted. 
     //In my case, do nothing, but you could display a message saying something like no db chosen etc. 
    } else { 

    $table = mysqli_real_escape_string($con, $_GET['table']); //escape it because it's an input, helps prevent sqlinjection. 

    $sql  = "SELECT * FROM " . $table; // SELECT * returns a list of ALL column data 
    $sql2 = "SHOW COLUMNS FROM " . $table; // SHOW COLUMNS FROM returns a list of columns 

    $result = mysqli_query($con, $sql); 
    $Headers = mysqli_query($con, $sql2); 

    //you could do more checks here to see if anything was returned, and display an error if not or whatever. 

    echo "<table border='1'>"; 
    echo "<tr>"; //all in one row 

    $headersList = array(); //create an empty array 

    while($row = mysqli_fetch_array($Headers)) { //loop through table columns 
     echo "<td>" . $row['Field'] . "</td>"; // list columns in TD's or TH's. 
     array_push($headersList, $row['Field']); //Fill array with fields 
    } //$row = mysqli_fetch_array($Headers) 

    echo "</tr>"; 

    $amt = count($headersList); // How many headers are there? 

    while($row = mysqli_fetch_array($result)) { 
     echo "<tr>"; //each row gets its own tr 
     for($x = 1; $x <= $amt; $x++) { //nested for loop, based on the $amt variable above, so you don't leave any columns out - should have been <= and not <, my bad 
      echo "<td>" . $row[$headersList[$x]] . "</td>"; //Fill td's or th's with column data 
     } //$x = 1; $x < $amt; $x++ 
      echo "</tr>"; 
    } //$row = mysqli_fetch_array($result) 

    echo "</table>"; 
    } 
    ?> 

Answer 2

$tablename = $_POST['table']; 
$result = mysqli_query($con,"SELECT * FROM $tablename"); 

$first = true; 

while($row = mysqli_fetch_assoc($result)) 
{ 
    if ($first) 
    { 
    $columns = array_keys($row); 
    echo "<table border='1'> 
     <tr>"; 
    foreach ($columns as $c) 
    { 
     echo "<th>$c</th>"; 
    } 

    echo "</tr>"; 
    $first = false; 
    } 
    echo "<tr>"; 
    foreach ($row as $v) 
    { 
    echo "<td>$v</td>"; 
    } 
    echo "</tr>"; 
} 
echo "</table>"; 

Answer 3

<?php 
    $table_name = do_not_inject($_REQUEST['table_name']); 
    $result = mysqli_query($con,'SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_NAME='. $table_name); 
?> 
<table> 
    <?php 
    $columns = array(); 
    while ($row = mysql_fetch_assoc($result)){ 
     $columns[]=$row['COLUMN_NAME']; 
     ?> 
     <tr><th><?php echo $row['COLUMN_NAME']; ?></th></tr> 
     <?php 
    } 

    $result = mysqli_query($con,'SELECT * FROM course'. $table_name); 
    while($row = mysqli_fetch_assoc($result)){ 
     echo '<tr>'; 
     foreach ($columns as $column){ 
     ?> 
      <td><?php echo $row[$column]; ?></td> 
     <?php 
     } 
     echo '</tr>'; 
    } 
    ?> 
</table>