内部连接mysql表

Question

Ok here it is. i have two tables: products and product_sizes

so basically my product table has id(primary key),name(product name)and size_id(foreign key from product_sizes)

my product_sizes table has predetermined values:

size_id      name
------------------
1            1x1
2            2x2
3            3x3

and here i have a working code displaying the product tables(in html using while code):

id      name         size_id
-----------------------------
1      product 1         1
2      product 2         2
3      product 3         1

my problem is that i want to display(in html) the size name rather than its size_id, something similar to these example:

id      name         size_id
-----------------------------
1      product 1        1x1
2      product 2        2x2
3      product 3        1x1

can someone teach me how to do this?.. i need it urgently for my final project. thank you. sorry for my explanation im not good in english.

Answer 1

Use a JOIN:

SELECT p.id,
       p.name,
       ps.name AS size_name
  FROM PRODUCT p
  JOIN PRODUCT_SIZES ps ON ps.size_id = p.size_id

See this link of a visual representation of the various JOINs .

<? include ("conn.php");
   $sql = "SELECT p.id,
                  p.name,
                  ps.name AS size_name
             FROM PRODUCT p
             JOIN PRODUCT_SIZES ps ON ps.size_id = p.size_id";
   $result = mysql_query($sql, $connection) or die(mysql_error());
   while($row = mysql_fetch_array($result)) {
?>
<tr>
  <td><? echo $row['id']; ?></td>
  <td><? echo $row['name']; ?></td>
  <td><? echo $row['size_name']; ?></td> 
</tr>
<? } ?>