如何获取一个表上的最后一个插入ID，以在另一个表上的另一个插入中使用它？

Question

Im trying to get id of the last inserted id on a table called authors to use it in another insert to a table called mail .

As you can see this is inserting a new author in table authors , and right after the insertion it must insert a welcome message to the new author in table mail .

Im using mysql_insert_id() but its not working. Nothing is saved to database and no errors occurs.

I know i should not use mysql_query but its ok, thats not the point here, just ignore this please.

if(!isset($row[email])){

    $sql = "INSERT INTO authors VALUES (NULL, 0, '".$email."', '".$username."', NULL, '".$first."', '".$fullname."', '".$first."', NULL, NULL, NULL, NULL,'http://www.gravatar.com/avatar/".md5(strtolower(trim($email)))."', 0);";
    mysql_query($sql);

    $sqlmsg = "INSERT INTO mail VALUES (NULL, 1, mysql_insert_id(), 'Welcome', Hello! Welcome to the website!', 'unread', NOW, 0, 0)";
    mysql_query($sqlmsg);

}   

Why nothing happens when a new author is inserted?

Thank you.

Answer 1

您需要将其串联在字符串中，

$sqlmsg = "INSERT INTO mail VALUES (NULL, 1, " . mysql_insert_id() . ", 'Welcome', Hello! Welcome to the website!', 'unread', NOW, 0, 0)";

Answer 2

Try saving it on a temporary variable before using it on the next query.

<?php
if(!isset($row[email])){

  $sql = "INSERT INTO authors VALUES (NULL, 0, '".$email."', '".$username."', NULL, '".$first."', '".$fullname."', '".$first."', NULL, NULL, NULL, NULL,'http://www.gravatar.com/avatar/".md5(strtolower(trim($email)))."', 0);";
  mysql_query($sql);

  $author_id = mysql_insert_id();

  $sqlmsg = "INSERT INTO mail VALUES (NULL, 1, $author_id, 'Welcome', Hello! Welcome to the website!', 'unread', NOW, 0, 0)";
  mysql_query($sqlmsg);

}   
?>

Answer 3

Use a select query on the table and order by 'id' desc with limit 1

select `id` from `authors` order by `id desc limit 1

will return the last id if it's auto incremented.