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.
Related
Just a little assistance, This is a pretty simple problem but it doesn't seem to work right. I am just comparing the value in a variable with all the values in a sql column. Same as if I were to compare a username input to the list of usernames in a sql column. This however is just to compare that the item id being stored in the column for that row is not an item id that is already in use.
I tested the value that I am getting back from the sql query and it is equal to the item id I typed in the input. What you will see below is the actual test to see if the id I am getting back is the one that I am looking for as well as the id of the row I can find that value in. The results I get is
2, 000002 (which is correct) that is what I am looking for.
$itemId = $_POST['itemId'];
if($sqlItemId = $dbCon->query("SELECT * FROM CVCinStoreCoins WHERE itemId = '$itemId'")){
while($data = $sqlItemId->fetch_assoc()){
printf("<p>%s, %s</p>", $data['id'], $data['itemId']);
die();
}
Then I took this out and tried to compare the value in the variable which is the same itemId already stored (000002). that is where I am going wrong.
I modified the code to look like this for further testing. Seems straight forward yet i am getting a FALSE response providing the latter echo statement "Item Id is not in use" But it is in the DB. I tried it a few different ways based on what I read in stackoverflow but none are giving me the right answer.
$sqlItemId = $dbCon->query("SELECT * FROM CVCinStoreCoins WHERE itemId = '$itemId'");
if($itemId == $sqlItemId){
echo "This item id is already in use. \n";
die();
} else {
echo "Item Id is not in use:";
die();
}
At one point I even tried a while statement to fetch the associated values prior to testing it but that didn't turn up a positive result either. Any suggestions?
Inside $sqlItemId you have the full table row (if any), not only its ID; change the SQL into a count and check the number of rows returned (if greater than 0 you have a duplicate):
$rowsCount = $dbCon->query("
SELECT COUNT(*)
FROM CVCinStoreCoins
WHERE itemId = '$itemId'
");
I don't know what $dbCon is (Doctrine DBAL? mysqli?) so I can't tell you how to use query's result.
Wy don't you just count it,
$result = $dbCon->query("SELECT COUNT(itemId) FROM CVCinStoreCoins WHERE itemId = $itemId");
if $result > 0
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.
I want to select all records from my table and loop through all those records until I get to the record where the numtimespaid column is equal to 0. Once I find that column I want to update it to 2 for that record and then exit out. Here is what I have that is not working correctly:
$query1 = "SELECT * FROM ".$line." ORDER BY datestamp, timestamp";
$result1 = mysql_query($query1) or die(mysql_error());
while($row = mysql_fetch_array($result1)){
if ($row[numtimespaid] == 0) {
$queryupdate="UPDATE ".$line." SET numtimespaid=1";
$resultu=mysql_query($queryupdate);
break;
}
}
Any ideas as to what I'm doing wrong and/or the right way of doing this?
There is no need whatsoever to loop over rowset from a SELECT statement. You can simply update the first row with that value. This query will update exactly one record matching numtimespaid = 0. If you want to update all rows matching that criterion, just remove the LIMIT 1.
$result = mysql_query("UPDATE $line SET numtimespaid=1 WHERE numtimespaid = 0 ORDER BY datestamp, timestamp LIMIT 1");
By the way, we don't know what the contents of $line are, but hopefully you have properly filtered that value if it comes from user input. If it does comes from user input, it's recommended to check its value against a whitelist of possible table names:
// $line can be one of table1,table2,table3
if (!in_array($line, array('table1','table2','table3')) {
// FAIL, don't execute the query
}
if ($row[numtimespaid] == 0) {
Generally gets interpreted as numtimespaid being an undefined constant. Put quotes around it, like this:
if ($row['numtimespaid'] == 0) {
Then, realize Michael's answer is just better overall.
Im using PHP to parse some XML, I take 3 details from each entry in the XML - Title, Description and ID.
The ID is unique and I store the ID along with title and description in a database. Im running the parse script via CRON so to prevent duplicates I want to first check the database to see if the ID of the entry already exists in the database.
How can I do this?
This will get my all the ID's right?
$id = mysql_query("SELECT id FROM updates");
$row = mysql_fetch_assoc($id);
if ($entry->id != $row) {
Insert
} else {
echo 'Duplicate';
}
Open to ideas?
Does that give me an array that I can compare the ID in the XML to?
$id = mysql_query("SELECT id FROM updates");
$row = mysql_fetch_assoc($id);
if ($entry->id != $row['id']) {
Insert
} else {
echo 'Duplicate';
}
it returns array form, so you have to give it column index or name to match
Try using INSERT ... ON DUPLICATE KEY UPDATE.
I would suggest that you have your DBMS handle conflicting ids.
you can use the ON DUPLICATE option of INSERT to handle that event let your DB automatically choose another ID.
$id = mysql_query("SELECT 1 FROM updates where id = " . $entry->id);
$row = mysql_fetch_assoc($id);
if ($row[0]) {
insert
}
else {
}
if uoy are makes the field unique then if you simply try to insert row - db rise an error "unique constraint". in this case you just have not to check if the record is unique. it will not be inserted anyway.
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.