SQL - 如何在另一个表中使用选定的ID？

Question

SQL TABLES：
user = ID，姓名，电子邮件..
hero = ID，名称，级别..
owner = userid，heroid

我有这两个问题：

$result = mysql_query("SELECT heroid FROM owner WHERE userid='$id'"); 
$heroid=mysql_fetch_row($result); 
$result2 = mysql_query("SELECT name FROM hero WHERE ID = 'heroid[0]'");

$heroname = mysql_fetch_row($result2);
echo "User $id has a character named $heroname[0]";
$heroname = mysql_fetch_row($result2); 
echo "User $id has a character named $heroname[0]";
..

这可以通过一个查询完成吗？

Answer 1

是。你可以这样做：

SELECT h.name
FROM hero h
INNER JOIN owner o ON o.heroid = h.id
WHERE o.userid = $id