Question

我尝试使用mysql和php从类别中获取数据。

Sql结构：

Category
-cat_id
-name
Date
-id
-url
-category

Php代码：

<?php
$sql = "select * from category";
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0)
{

while ($row = mysql_fetch_assoc($result))
    {
echo '<option value="'.$row["cat_id"].'">'.$row["name"].'</option>';
    }
}



$sql = "select * from date WHERE category='1'";
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0)
{
while ($row = mysql_fetch_assoc($result))
    {
echo '.$row["url"].';
    }
}

?>

当我选择类别时，未列出数据。有什么想法吗？

Answer 1

试试此代码。刚删除单引号

$sql = "select * from date WHERE category='1'";
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0)
{
while ($row = mysql_fetch_assoc($result))
{
  echo $row["url"];
}
}

Answer 2

这可行： PHP代码

 <?php
    $sql = "select * from category";
    $result = mysql_query($sql);
    if(mysql_num_rows($result) > 0)
    {

    while ($row = mysql_fetch_assoc($result))
        {
    echo '<select id="category" name="category">';
    echo '<option value="'.$row["cat_id"].'">'.$row["name"].'</option>';
    echo '</select>';        
    }
    }



    $sql = "select * from date WHERE category='1'";
    $result = mysql_query($sql);
    if(mysql_num_rows($result) > 0)
    {
    while ($row = mysql_fetch_assoc($result))
        {
    echo 'url is: '.$row["url"];
        }
    }

    ?>

Answer 3

试试这个

$sql = "select * from date WHERE category='1'";
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0)
{
    while ($row = mysql_fetch_assoc($result))
    {
       echo $row["url"];
    }
}


if you want result with in single quotes 

$sql = "select * from date WHERE category='1'";
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0)
{
   while ($row = mysql_fetch_assoc($result))
   {
       echo "'".$row["url"]."'";
   }
}

Answer 4

请避免使用mysql_*，因为PHP7中的mysql_*功能已被删除。请改用MySQLi。

PHP + Mysql：

<?php
$sql = "select * from category";
$result = mysql_query($sql);

echo "<select name='category'>";
if(mysql_num_rows($result) > 0)
{
    while ($row = mysql_fetch_assoc($result)) {
        echo '<option value="'.$row["cat_id"].'">'.$row["name"].'</option>';
    }
}
echo "</select>";


if(!empty($_POST['category'])) {
    $category_id = $_POST['category'];

    $sql = "select * from date WHERE category = '".$category_id."'";
    $result = mysql_query($sql);

    if(mysql_num_rows($result) > 0) {
        while ($row = mysql_fetch_assoc($result))
        {
            echo '.$row["url"].';
        }
    }
}
?>

PHP + Mysqli

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

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

$sql = "select * from category";
$result = $conn->query($sql);

echo "<select name='category'>";
if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        echo '<option value="'.$row["cat_id"].'">'.$row["name"].'</option>';
    }
} 
echo "</select>";

if(!empty($_POST['category'])) {
    $category_id = $_POST['category'];

    $sql = "select * from date WHERE category = '".$category_id."'";
    $result = $conn->query($sql);

    if($result->num_rows > 0) {
        while ($row = $result->fetch_assoc())
        {
            echo '.$row["url"].';
        }
    }
}
$conn->close();
?>

Answer 5

没有任何改变。

我正在使用此代码：

<?php
$sql = "select * from category";
$result = mysql_query($sql);

echo "<select name='category'>";

if(mysql_num_rows($result) > 0)

{
while ($row = mysql_fetch_assoc($result)) {
    echo '<option value="'.$row["cat_id"].'">'.$row["name"].'</option>';
}
}

echo "</select>";


if(!empty($_POST['category'])) {

$sql = "select * from date WHERE category = '1'";
$result = mysql_query($sql);

if(mysql_num_rows($result) > 0) {
    while ($row = mysql_fetch_assoc($result))
    {
        echo $row["url"];
    }
}
}

?>

如果我删除了条件，那么列出数据但始终是。

使用php mysql从类别中获取数据

5 个答案: