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Question

how to retrieve the last stored record information from a database table

Forum|Forum|13 years ago
March 31, 2013
7 replies
2026 views

Hi all,

I have a slight problem with retrieval of records.

Currently, I have a form with reservation number (an auto incremental primary key of my table), ISBN (a primary key from my books table), Email (a primary key from my users table), number of orders, and collection date.

My reservation number and collection date are hidden textfields while ISBN and email are read only textfield. So when users key in number of orders, it will insert a record into my reservation table in my database and i will be redirected to reservation confirmation page.

How do i show the reservation number immediately on my reservation confirmation page?

Is it to use mysql_insert_id() ?

If I am supposed to use it, how should i place it?

Please elaborate more as I am quite new to php. Thanks!

This topic has been closed for replies.

David_Powers

Inspiring

Your description is rather confusing. You say that the reservation number is an auto-increment primary key, but you also say that it's a hidden field in your form. So, what are you actually doing?

If the reservation number is in a hidden field, it presumably refers to an existing record in your database. You can use that primary key to update the record, but you can't use it to insert a new record. Inserting a new record will generate a new primary key.

As Murray, says, you can get the latest number by using DESC to get the results in reverse order.

My main concern is that you're new to PHP, yet you're using deprecated mysql functions, such as mysql_insert_id(). I suspect that you're also using Dreamweaver server behaviors. In a word, DON'T. They haven't been updated for many years, and they use outdated code, which will eventually stop working. Although it will take time to learn how to write your own PHP code, you'll be glad in the end.

MurraySummers

Inspiring

THe easy way to get the last stored record is to sort the recordset in DESC order by record ID in your SQL statement. The first one will then be the last one added. Using mysql_insert_id() is OK too, but it should be done immediately below the SQL statement, and assigned to a variable at that point.

B

bregent

Participating Frequently

>THe easy way to get the last stored record is to sort the recordset in DESC

>order by record ID in your SQL statement. The first one will then be the last one added

Murray, that technique is not safe because the returned value may not necessarily be the last one inserted by the current connection. In other words, if two people are inserting rows at the same time, the SELECT statement can return the wrong value. This is known as a race condition. mysql_insert_id, or its equivalent PDO function, ensures the value return is the one last inserted by the current connection.

I

IVYYAuthor

Known Participant

Hi bregent,

You have mentioned that I should use mysql_insert_id.

May I know how do i apply mysql_insert_id? I am clueless in going about doing it. Do I put it in my reservation page or reservation confirmation page?

Thanks!

David_Powers

Inspiring

I have moved this thread to the Develop server-side applications in Dreamweaver forum, which is a more appropriate place for such discussions.

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