从数据库的两个表中检索数据并使用php显示它[关闭]

Question

I have created a database named (insert) having two tables table1 and table 2.

table1 have 3 columns user, id, roll.

table2 have 2 columns id, menu.

I have inserted values in two tables. I want to retrieve all values from two tables and show them in another php file, but my query is not working. It's showing error. What should I do? here is my code

<?php

include 'insertjoincon.php';
$sql = "SELECT table1.user, id FROM table1, table2 WHERE    table1.id=table2.id";

echo "<table border=1>
<tr><th>Name</th><th>ID</th></tr>
";

while ($line = mysql_fetch_array($sql)) {
    $name = $line["user"];
    $id = $line["id"];
    echo "<tr>";
    echo "<td>" . $name . "</td>";
    echo "<td>" . $id . "</td>";
    echo "</tr>";

    echo "</table>";
}

$conn->close();
?>

Answer 1

(Edit: The first few sentences are incorrect. In my first glance I saw that you specified a table for one column but missed that you didn't specify a table for id. Because they share the same value, pick one table and specify it. You should always specify table with either explicit or implicit JOINS. Still, first thing's first).

I'm guessing your query actually works if you test it. There is nothing inherently wrong with your query (although I always recommend using explicit JOINS).

There is a good reason why the example code you're providing would not work...

You're missing $result = mysqli_query($sql):

Yok can then use mysqli_fetch_array($result).

mysqli_fetch_array() expects a result, not a SQL string.

Please note that you should use mysqli not mysql.