Getting Auto Increment multiple times - php

I'm hoping someone can help me figure out what I thought would be really easy.
I have a form that I dynamically add rows to. When I add the row, I want to display a unique value, and am using the MySql table primary key - called ID. Because there will be multiple users, I want to immediately reserve that ID, so it doesn't get reused. Since a user may decide to add another item to the list, and add another dynamic row, I want to repeat the process (get the new Auto Increment value from that table, and immediately reserve it).
Unfortunately, I continue to get the same ID value, even though I have confirmed the auto increment value has increased.
This is what I am using inside my "add row" function before I use the DOM Element to add the row:
$result = mysql_query("SHOW TABLE STATUS LIKE 'table'");
$row = mysql_fetch_array($result);
$nextId = $row['Auto_increment'];
$query = "INSERT INTO table (id, identifier1, identifier2) VALUES ('".$nextId."','".$identifier1."','".$identifier2."')";
$result = mysql_query($query) or die(mysql_error());
I have tried adding immediately before them the following in the hopes that it will blank everything and pull all new values:
$nextId = 0;
$row = "";
$result = "";
$query = "";
I am hoping someone out there can see something simple or suggest a better way that will work.
Thanks in advance.

Ok as your comment shows you have a slight mistake in your INSERT, try this:
$query = "INSERT INTO table (identifier1, identifier2)
VALUES ('".$identifier1."','".$identifier2."')";
$result = mysql_query($query) or die(mysql_error());
$nextId = mysql_insert_id()+1; //you also need to +1 to get the next number
But there is NO guarentee that the next id will be +1 from the last.

Related

PHP function doesn't increment int as it should

On my XAMPP server I have a database table on phpMyAdmin. In that table, I have a few columns, and one of them is id column (Integer).
I want to get the latest added item's ID, increment it by one and then assign it to a new item that the function adds to the table.
The problem is that whenever there is a new item, it is automatically assigned with 1 as id, nothing above 1.
$sql = "SELECT * FROM items";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while ($row = $result->fetch_assoc()) {
if( $_SESSION["increment"] == "yes"){
$_SESSION["id"] = $row["id"];
}else
$_SESSION["id"]=$_SESSION["id"]+1;
}
} else {
$_SESSION["id"] = 1;
}
This will give you last increment Id.
$sql = "SELECT id FROM items order by id DESC LIMIT 0,1";
Then you dont want have a while loop to find last increment Id.
error reporting said what? and mysqli_error($conn)?
-- Fred-ii-
The above request by Fred -ii- sums it up, if your ->num_rows is returning zero or not a number (false) then you have an SQL error, so you need to check your error logs, and check your database connection.
Have you started your session with session_start?
Do you intend that the first else calls without brackets, only executing the single following line, $_SESSION["id"]=$_SESSION["id"]+1; ?
It seems to me that you need well known AUTO_INCREMENT functionality built inside MySQL database. Just define in your database schema for your table that column is AUTO_INCREMENT column type, and it will be automatically incremented by 1 upon each new insert into table.

Updating array values for a particular id in database

Im working on a web application where i need to let users update several tds in a tr of a table. As of now i can fetch and show the database values in the respective td's. But when i try to update them, the last entered values in the last tr gets updated for all the td's in the table.
Below is the part of the query im trying. All the values are considered array since values are gathered from several input box.
$cno="123";
$c = count($ndv);
for($i=0;$i<$c;$i++)
{
$query_dv="UPDATE device SET cid = '$cno',name = '$ndv[$i]',type = '$tdv[$i]',serialno = '$sdv[$i]',model = '$mdv[$i]',location = '$ldv[$i]' WHERE cid = ".$cno;
$sql_device = mysqli_query($conn, $query_dv) or die(mysqli_error($conn));
}
so say right now i try to update with values 123,1,1,1,1,1 and 123,2,2,2,2,2
i get 123,2,2,2,2,2 and 123,2,2,2,2,2 .. i do understand that its getting reupdated due to the for loop. So im trying to fix this part of the code. And im struggling to fix it. Any help would be appreciated.
Your issue is you are not uniquely identifying the row you are wanting to update, todo this add a column to your database called something like id make it the primary key and have it auto increment, then in your table add a hidden/disabled input containing the id and update your query to be something along the lines of
$query_dv="UPDATE device SET name = '$ndv[$i]',type = '$tdv[$i]',serialno = '$sdv[$i]',model = '$mdv[$i]',location = '$ldv[$i]' WHERE id = " . $id[$i];
I removed the update for cid because from your question it doesn't look like it changes so no need to update.

add one (+1) to a field in mysql database using php

I have a php script that displays records from a database. It's probably not the best script, as I'm very new to php.
I've added an additional column in my table and would like to keep a count in that column to show me how many times each of the records have been viewed.
Heres the part of the code I think i need to add the code to... if i need to post the entire page i will, but i just figured i could add the line to this part.
//Get the details from previous page
$SelectedCounty = $_POST["result"];
//set variable for next SEARCH
$option = '';
// Get the county names from database - no duplicates - Order A-Z
$query = "SELECT DISTINCT tradingCounty FROM offers ORDER BY tradingCounty ASC";
// execute the query, $result will hold all of the Counties in an array
$result = mysqli_query($con,$query);
while($row = mysqli_fetch_array($result)) {
$option .="<option>" . $row['tradingCounty'] . "</option>";
}
}
the new column name is 'views' and i just want to add 1 to it each time a record from the database is viewed.
any help greatly appreciated.
Add a new field views to the table.
When, user views the page, fire the SQL.
$query = "UPDATE offers SET views = views + 1";
mysqli_query($con,"update offers set views = views + 1");
If you have added the column, it probably has a NULL value. Either set the value to 0, by doing:
update offers
set views = 0;
Or use:
update offers
set views = coalesce(views, 0) + 1;
You can change your code with this rewritten code assuming that your Table has a column views (datatype int).
//Get the details from previous page
$SelectedCounty = $_POST["result"];
//set variable for next SEARCH
$option = '';
// Get the county names from database - no duplicates - Order A-Z
$query = "SELECT DISTINCT tradingCounty FROM offers ORDER BY tradingCounty ASC";
// execute the query, $result will hold all of the Counties in an array
$result = mysqli_query($con,$query);
if($result){
$query2 = "UPDATE offers SET views=views+1;
mysqli_query($con,$query2);
}
while($row = mysqli_fetch_array($result)) {
$option .="<option>" . $row['tradingCounty'] . "</option>";
}
Or if you need to track the view counts for individual records, you need to modify your code a bit. And probably you need to add one more field in the database for eg. id (datatype int) which can distinguish between different records.
Please clear your problem properly.
As far as i have analysed your code it brings out the following case.
There are different records for tradingConty, and whenever a user views that particular record(one of the tradingCounty record) by clicking that or any other action specified, the php script is set to increament the view count for that particular entry(we can get that by id) in the database.
If thats the scenario, we can easily generate a code accordingly.

How to use count in php?

I want to insert data to database. I have a table, named member that has 7 column (ID, User, Password, Address, Phone, Gender, Email). I used count to make auto number like this
$no = "SELECT COUNT(ID)FROM member";
$nors = mysql_query($no);
$nors = $nors + 1;
$query = "INSERT INTO member VALUES (".$nors.",'".$user."','".md5($pass)."','".$name."','".$addr."',".$hp.",'".$gender."','".$email."')";
Why, the result of nors is 6 not 2, although I only have 1 data?
mysql_query returns a result object, not the value. Your query also lacks a needed space between COUNT(ID) and FROM...
$no = "SELECT COUNT(ID) AS count FROM member";
$result = mysql_query($no);
$row = mysql_fetch_object($result);
$nors = $row->count;
You should consider using something more modern like PDO, though, as mysql_* functions have been deprecated and will eventually go away entirely.
edit: #andrewsi noted in the comments that you really should be using MySQL's built-in auto increment functionality for IDs, anyways. Much better than what you're currently doing.
If you're using this to generate the next ID number for a new member, you should look at making ID an auto_increment field instead - as it stands, it's possible that you'll get two members signing up at the same time, and both getting assigned the same ID
Replace this line
$nors = mysql_query($no);
By these lines :
$result_handler = mysql_query($no);
$result = mysql_fetch_array($result_handler);
$nors = $result[0];
If your id field is set to be an auto number you don't need to insert it. MySql will handle that for you. Anytime you add a new row the autonumber is incremented. If you delete a row the autonumber does not decrement.
If you currently only have 1 row but you've added and deleted rows then your insert will produce a row with an ID that is not consecutive.

Setting status of other rows after INSERT

Hey, I have a field called STATUS and it is either 1 to show or 0 to hide. My code is below. I am using an edit in place editor with jQuery. Everytime you update it creates a new ROW which I want, but I want only the new one to have STATUS = 1 and the others to 0. Any ideas on how I would do that?
<?php
include "../../inc/config.inc.php";
$temp = explode("_", $_REQUEST['element_id'] );
$field = $temp[0];
$id = $temp[1];
$textboxval = stripslashes(mysql_real_escape_string(preg_replace('/[\$]/',"",$_REQUEST["update_value"])));
$query = "INSERT INTO notes ($field,status,date,c_id) VALUES ('$textboxval','1',NOW(),'$id')";
mysql_query($query);
echo($_REQUEST['update_value']);
?>
I am not sure exactly what you mean - do you want to make all the entries except the new one have status = 0? If so, just issue an update before the insert:
UPDATE notes SET status = 0
However, I should also note that you have a potential SQL injection to worry about. By stripping slashes after applying "mysql real escape string", you are potentially allowing someone to put text in your SQL statement that will execute an arbitrary SQL statement.
Something like this, sorry for the post before, I mis read it the first time then went back:
<?php
include "../../inc/config.inc.php";
$temp = explode("_", $_REQUEST['element_id'] );
$field = $temp[0];
$id = $temp[1];
$textboxval = mysql_real_escape_stringstripslashes((preg_replace('/[\$]/',"",$_REQUEST["update_value"])));
// set older entries to 0 - to not show but show in history
$hide_notes = "UPDATE notes SET status = 0";
mysql_query($hide_notes);
// add new entry with status of 1 to show only latest note
$query = "INSERT INTO notes ($field,status,date,c_id) VALUES ('$textboxval','1',NOW(),'$id')";
mysql_query($query);
echo($_REQUEST['update_value']);
?>
i just ran in to a problem I didn't of the set up of my table doesn't allow me to show more than one client a time and i will be having numerous clients, my bad on planning ha
You really want to get the ID of the newly generated row and then trigger an UPDATE where you all rows where the ID is not the new row, e.g.
UPDATE notes SET status = 0 WHERE id != $newly_generated_id
If the ID column in your table is using AUTO_INCREMENT you can get its ID via "SELECT LAST_INSERT_ID()" and then use the return value in that statement in your UPDATE statement.
Pseudo code:
$insert = mysql_query("INSERT INTO ...");
$last_id = mysql_query("SELECT LAST_INSERT_ID()");
$update = mysql_quqery("UPDATE notes SET status = 0 WHERE id != $last_id");
The only caveat to this approach is where you might have a brief moment in time where 2 rows have status=1 (the time between your INSERT and the UPDATE). I would wrap all of this in a transaction to make the whole unit more atomic.

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