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I'm uploading image file to storage server. Before uploading I should compose filename, which contains AUTOINCREMENT VALUE in it (for example, 12345_filename.jpg).

How could I get autoincrement value before inserting into DB?

I see only one solution

  1. insert empty row
  2. get it's autoincrement value
  3. delete this row
  4. insert row with real data using autoincrement value from p.1

Is there any other solutions?

Thank you

 Answers

1

The autoincrement value is generated by the database itself, when the insertion is done ; which means you cannot get it before doing the actual insert query.

The solution you proposed is not the one that's often used -- which would be :

  • insert some half-empty data
  • get the autoincrement value that's been generated
  • do your calculations, using that autoincrement value
  • update the row to put the new / full data in place -- using the autoincrement generated earlier in the where clause of the update query, to identify which row is being updated.

Of course, as a security precaution, all these operations have to be made in a transaction (to ensure a "all or nothing" behavior)


As pseudo-code :

begin transaction
insert into your table (half empty values);
$id = get last autoincrement id
do calculations
update set data = full data where id = $id
commit transaction
Sunday, September 4, 2022
2

I would say just build it yourself. You can set it up like this:

$query = "INSERT INTO x (a,b,c) VALUES ";
foreach ($arr as $item) {
  $query .= "('".$item[0]."','".$item[1]."','".$item[2]."'),";
}
$query = rtrim($query,",");//remove the extra comma
//execute query

Don't forget to escape quotes if it's necessary.

Also, be careful that there's not too much data being sent at once. You may have to execute it in chunks instead of all at once.

Saturday, November 5, 2022
3

use mysql_fetch_assoc - it will return

array( "name" => "value", "name2" => "value2" ... );

then use json_encode( $data )

Thursday, September 29, 2022
2

The function you're looking for is find_in_set:

 select * from ... where find_in_set($word, pets)

for multi-word queries you'll need to test each word and AND (or OR) the tests:

  where find_in_set($word1, pets) AND find_in_set($word2, pets) etc 
Wednesday, August 17, 2022
2

Use PHP's $_POST or $_GET superglobals to retrieve the value of the input tag via the name of the HTML tag.

For Example, change the method in your form and then echo out the value by the name of the input:

Using $_GET method:

<form name="form" action="" method="get">
  <input type="text" name="subject" id="subject" value="Car Loan">
</form>

To show the value:

<?php echo $_GET['subject']; ?>

Using $_POST method:

<form name="form" action="" method="post">
  <input type="text" name="subject" id="subject" value="Car Loan">
</form>

To show the value:

<?php echo $_POST['subject']; ?>
Thursday, October 6, 2022
 
isea
 
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