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Posted by x0054 on 07/17/06 02:54
"ImOk" <jon.macaroni@gmail.com> wrote in
news:1152903982.691416.105900@m79g2000cwm.googlegroups.com:
>>From the docs:
>
> LAST_INSERT_ID([expr])
> Returns the last automatically generated value that was inserted into
> an AUTO_INCREMENT column. See section 8.1.3.130 mysql_insert_id().
> mysql> SELECT LAST_INSERT_ID();
> -> 195
>
> The last ID that was generated is maintained in the server on a
> per-connection basis. It will not be changed by another client. It
> will not even be changed if you update another AUTO_INCREMENT column
> with a non-magic value (that is, a value that is not NULL and not 0).
> If you insert many rows at the same time with an insert statement,
> LAST_INSERT_ID() returns the value for the first inserted row. The
> reason for this is to make it possible to easily reproduce the same
> INSERT statement against some other server. If expr is given as an
> argument to LAST_INSERT_ID(), then the value of the argument is
> returned by the function, and is set as the next value to be returned
> by LAST_INSERT_ID(). This can be used to simulate sequences: First
> create the table:
> mysql> CREATE TABLE sequence (id INT NOT NULL);
> mysql> INSERT INTO sequence VALUES (0);
>
> Then the table can be used to generate sequence numbers like this:
> mysql> UPDATE sequence SET id=LAST_INSERT_ID(id+1);
>
> You can generate sequences without calling LAST_INSERT_ID(), but the
> utility of using the function this way is that the ID value is
> maintained in the server as the last automatically generated value
> (multi-user safe). You can retrieve the new ID as you would read any
> normal AUTO_INCREMENT value in MySQL. For example, LAST_INSERT_ID()
> (without an argument) will return the new ID. The C API function
> mysql_insert_id() can also be used to get the value. Note that as
> mysql_insert_id() is only updated after INSERT and UPDATE statements,
> so you can't use the C API function to retrieve the value for
> LAST_INSERT_ID(expr) after executing other SQL statements like SELECT
> or SET.
>
> x0054 wrote:
>> Ok, this is a stupid problem, I admit. I have a scrip that adds
>> records to a table. The records are for photos. So, after adding a
>> record the scrip also uploads a picture from users computer and
>> renames it to {$recordID}.jpg.
>>
>> The problem is, my recordID field is auto incrementing in mySQL. So
>> currently I just take the last added record and assume that it the
>> one I just added, and rename the file to the recordID of that record.
>> It works, but clearly isn't the best way to do this as 2 users can
>> add records at the same time and then I would have a problem.
>>
>> So what I am wondering is if there is a way to write a record to
>> mySQL and then have mySQL return recordID of the record just written?
>>
>> - Bogdan
>
>
Thank you very much, that's exactly what I was looking for.
- Bogdan
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