使用临时表在字段mysql中插入新名称

Question

I am creating a duplicate functionality in my application, this duplicates an entire vacancy with the following code, in the example i am duplicating from vacancy id 94 (which has banner name "image.jpg":

$vacdata = $this->vacancies_model->get($data['old_vacancy_id']);
$newvacbannername = return_unique_filename($vacdata->banner);
copy_file($vacdata->banner, $newvacbannername);
$data['newvacancyid'] = $this->vacancies_model->duplicate($data['old_vacancy_id'], $newvacbannername);

In the $newvacbannername there is the string "image_8.jpg". Which is the unique name of my new file name which i copy, the copy is working as intended.

The function duplicate looks like this:

function duplicate($vacid, $banner)
{
    $this->db->query('CREATE TEMPORARY TABLE tmptable SELECT * FROM vacancies WHERE vacancy_id = ' . $vacid);
    $this->db->query('UPDATE tmptable SET vacancy_id = NULL');
    $this->db->query('UPDATE tmptable SET banner = ' . $banner );
    $this->db->query('UPDATE tmptable SET create_time = now()');
    $this->db->query('UPDATE tmptable SET watch_counter = 0');
    $this->db->query('UPDATE tmptable SET contact_info_counter = 0');
    $this->db->query('UPDATE tmptable SET status = 0');
    $this->db->query('UPDATE tmptable SET reminder_mail_sent = 0');
    $this->db->query('UPDATE tmptable SET extend_code = NULL');
    $this->db->query('INSERT INTO vacancies SELECT * FROM tmptable');
    $newvacancyid = $this->db->insert_id();
    $this->db->query('DROP TEMPORARY TABLE IF EXISTS tmptable');
    return $newvacancyid;
}

I tried doing a var_dump on $banner to make sure that this variable contains the correct string, and it does contain image_8.jpg. So it just copies the banner from the original vacancy but it does not set the new banner name

If i look at the SQL that was executed i see the following results:

0.0076 CREATE TEMPORARY TABLE tmptable SELECT * FROM vacancies WHERE vacancy_id = 94

0.0090 UPDATE tmptable SET vacancy_id = NULL

0.0000 UPDATE tmptable SET banner = image_8.jpg

0.0005 UPDATE tmptable SET create_time = now()

0.0023 UPDATE tmptable SET watch_counter = 0

0.0001 UPDATE tmptable SET contact_info_counter = 0

0.0002 UPDATE tmptable SET status = 0

0.0002 UPDATE tmptable SET reminder_mail_sent = 0

0.0002 UPDATE tmptable SET extend_code = NULL

0.0153 INSERT INTO vacancies SELECT * FROM tmptable

However if i look in mysql itself for the new vacancy duplicated, the row it inserted everything in the update statement works except for the $banner, it inserted the exact same name as in the original vacancy (image.jpg in this example instead of image_8.jpg).

Answer 1

Why not just do:

INSERT INTO vacancies
    SELECT
    NULL, --id field
    other_columns,
    go_here,
    NULL,
    :banner, --bind this from $banner,
    now(),
    0,
    0,
    0,
    0,
    NULL
    FROM vacancies
    WHERE vacancy_id = ' . $vacid

Seems like a stretch to involve a temporary table, and a ton of queries, when you can simply do this in one. Also: Look into binding variables to your query: It's much safer, and the recommend approach.

Alternatively, you can also do this via a transaction:

START TRANSACTION;

INSERT INTO vacancies
SELECT
*
FROM vacancies
WHERE vacancy_id = :vacid;

UPDATE vacancies
SET banner = :banner,
create_time = now(),
watch_counter = 0,
...
WHERE vacancy_id = :vacid --Get the inserted ID from mysql_insert_id();

COMMIT;