Persistent Database Connections and mysql_insert_id() - php

Description :
I have an SQL query that inserts the data into the table (I AM USING MYSQL)
Then I have another sql query that inserts data into another table with an id of the data inserted before it... I achieved it couple of months ago using a very rookie method like this
if(mysqli_query($con,
"INSERT INTO `plumit`.`posts` (
`posted_on_id`,
`poster_id`,
`post_type` ,
`post` ,
`likes` ,
`dislikes` ,
`comments` ,
`post_date`
) VALUES (
'$posted_on_id',
'$reg_no',
'text',
'$data',
'0',
'0',
'',
'$datetime'
)")
){
$result = mysqli_query($con,
"select * from posts order by post_id desc limit 1"
);
while ($rows=mysqli_fetch_array($result,MYSQLI_BOTH))
{
$post_id = $rows[0];
}
if(mysqli_query("insert into another table using $post_id"))
{
echo "Success";
}
}
now I am changing all my code because right now I am making too much requests to the server for queries and have started to learn how to optimize the code and use smarter ways of quering the database...
In order to get the last inserted id I used mysql_insert_id() instead of using the select statement
but that returned me nothing but 0.
So after a lot of searching I found out that I have to create persistent database connections in order to make it work So I included this in my php file I am using to insert data
$cfg['PersistentConnections'] = TRUE;
but that didn't work either if you Google it there are many links that say that creating persistent connections is a very bad idea etc...
All I want is to get the id of the row I inserted not last inserted row because if I get the ID of the last inserted row it can be the id of a different row lets say while i am getting the last id some one else inserts the data so it'll get the id of that row which is wrong ... there will 1000 of users inserting the data and I want the id of the row I just inserted and I have no idea what to do now ?? Any body ?

Related

INSERT where doesn't exist in php script, comparing 2 tables

I currently have a script that runs every 5 minutes and selects the data from a table on server 1 and an identical table on server2. This is a workaround for replication, essentially, since we don't have that option currently.
The script is successful but I've realized that it misses records sometimes, for whatever reason. The current script selects all records from the destination table, stores the max primary key, selects all data from the source table and then inserts anything with a greater Primary key into the dest. table.
I'd like to modify the script slightly and instead of using max id, just say "if a row has an primary key that doesn't exist in the destination table, insert that row there."
Again these are cloned tables so the structure is the same and they both use AI Primary Keys.
Here's the current working script:
$latest_result = $conn2->query("SELECT MAX(`SESSIONID`) FROM
`ambition`.`session`");
$latest_row = $latest_result->fetch_row();
$latest_session_id = $latest_row[0];
//Select All rows from the source phone database
$source_data = mysqli_query($conn, "SELECT * FROM
`cdrdb`.`session` WHERE `SESSIONID` > $latest_session_id");
// Loop on the results
while($source = $source_data->fetch_assoc()) {
// Check if row exists in destination phone database
$row_exists = $conn2->query("SELECT SESSIONID FROM
ambition.session WHERE SESSIONID = '".$source['SESSIONID']."' ") or
die(mysqli_error($conn2));
//if query returns false, rows don't exist with that new ID.
if ($row_exists->num_rows == 0){
//Insert new rows into ambition.session
$stmt = $conn2->prepare("INSERT INTO ambition.session (SESSIONID,
SESSIONTYPE,CALLINGPARTYNO,FINALLYCALLEDPARTYNO,
DIALPLANNAME,TERMINATIONREASONCODE //etc. There are a lot of columns so I
ommitted the others
Is there a way I can slightly modify this to just insert what doesn't exist rather than relying on the MAX ID?
Or is there something here that would be a culprit as to why it's missing records?
You could use INSERT INTO SELECT and check if value is already in target:
INSERT INTO trg_table (cols)
SELECT cols
FROM src_table s
WHERE NOT EXISTS (SELECT 1 FROM trg_table t WHERE t.id = s.id);

putting values in between the ascending database column

Following is my database in mysql:
Id Username Password
1 admin admin
2 jay jay1
3 suman xyza
4 chintan abcde
This is my code in php:
$fetchid = mysql_query(" SELECT MAX(Id) As max From user;");
$row = mysql_fetch_array($fetchid);
$largest = $row['max'];
$largest++;
$user= $_POST['username'];
$pass= $_POST['password'];
$result = mysql_query(" INSERT INTO `proshell`.`user` (
`Id` ,
`Username` ,
`Password`
)"."
VALUES (
'".$largest."', '".$user."', '".$pass."'
);");
Problem:
Now if I delete row with Id=1 and then re-enter the data then it should use ID=1 then Again I reinsert the data it use ID=5
It works like this:
if I delete row with Id=1 and then re-enter the data the Id it gets is 5 but then 1 is free so,
What should I write to perform that task.
First, if you set your Id column to AUTO_INCREMENT you don't need the following part in your code at all:
$fetchid = mysql_query(" SELECT MAX(Id) As max From user;");
$row = mysql_fetch_array($fetchid);
$largest = $row['max'];
$largest++;
Because AUTO_INCREMENT will automatic add new value to your ID colume.
But if you don't set it to AUTO_INCREMENT, the above code will grab the MAXIMUM ID value (in this case, 4).
When you re-enter your data again after you delete the row 1, the MAXIMUM ID still 4, so your new ID value will be 5 (from $largest++;).
.....
If you really need to use consecutive ids as you PK, you need to re-write you code but I suggest you to use UUID for you ID column instead.
You can easily generate UUID by using uuid().
How about the UUID performance? Refer to Dancrumb's answer about this:
A UUID is a Universally Unique ID. It's the universally part that you should be considering here.
Do you really need the IDs to be universally unique? If so, then UUIDs
may be your only choice.
I would strongly suggest that if you do use UUIDs, you store them as a
number and not as a string. If you have 50M+ records, then the saving
in storage space will improve your performance (although I couldn't
say by how much).
If your IDs do not need to be universally unique, then I don't think
that you can do much better then just using auto_increment, which
guarantees that IDs will be unique within a table (since the value
will increment each time)
see. UUID performance in MySQL?
EDIT: I don't suggest you run query on the whole table just to find the MAX ID value before inserting new value everytime, because it will give you a performance penalty (Imagine that if you have million rows and must query on them everytime just to insert a new row, how much workload causes to your server).
It is better to do the INSERT just as INSERT, no more than that.
EDIT2:
If you really want to use consecutive ids, then how about this solution?
Create new TABLE just for store the ids for insert (new ids and the ids that you deleted).
For example:
CREATE TABLE cons_ids (
ids INT PRIMARY KEY,
is_marker TINYINT DEFAULT 0
);
then initial ids with values from 1-100 and set marker to be '1' on some position, e.g. 80th of whole table. This 'marker' uses to fill your ids when it's nearly to empty.
When you need to INSERT new Id to your first table, use:
$result = mysql_query("SELECT ids, marker FROM cons_ids ORDER BY ids ASC LIMIT 1;");
$row = mysql_fetch_row($result);
and use $row[0] for the following code:
INSERT INTO yourtable (Id, Username, Password)
VALUES ($row[0], $username, $password);
DELETE FROM cons_ids
WHERE ids = $row[0];
This code will automatically insert the lowest number in cons_ids as your Id and remove it from the cons_ids table. (so next time you do insert, it will be the next lowest number)
Then following with this code:
if ($row[1] == 1) {
//add new 100 ids start from the highest ids number in cons_ids table
//and set new marker to 80th position again
}
Now each time you delete a row from your first table, you just add the Id from the row that you deleted to cons_ids, and when you do INSERT again, it will use the Id number that you just deleted.
For example: your current ids in cons_ids is 46-150 and you delete row with Id = 14 from first table, this 14 will add to your cons_ids and the value will become 14, and 46-150. So next time you do INSERT to your first table, your Id will be 14!!.
Hope my little trick will help you solve your problem :)
P.S. This is just an example, you can modify it to improve its performance.
First of all, as I understand, you are selecting highest column ID which should be always the last one (since you set auto-increment on ID column).
But what are you trying to do is actually filling up holes after delete query, right?
If you are really looking for such approach, try to bypass delete operation by making new boolean column where you flag record if it is active or not (true/false).
SQL table change:
Id Username Password Active
1 admin admin false
2 jay jay1 true
3 suman xyza false
4 chintan abcde true
PHP request:
$fetchid = mysql_query(" SELECT MIN(Id) As min FROM user WHERE active = false;");
$result = mysql_query(" INSERT INTO `proshell`.`user` (
`Id` ,
`Username` ,
`Password`
`Active`
)"."
VALUES (
'".$largest."', '".$user."', '".$pass."', 'true'
);");

Get sql Id and insert it into another query instantly

I have two tables first called messages and the other called messages_reply.
I used this code to insert into messages table:
$query = "INSERT INTO `messages` VALUES('', '$id', '$otherId', '')";
$query_run = mysqli_query($connect, $query);
I have the first column auto_increment thats why I left it empty by writing ''
Now i want this auto_increment value that i have inserted to be inserted in the other table called messages_reply
Do I have to create another query to return it or there is an instant way to insert it here and there?
you have to select the last id on table messages first, then you can insert that last id + 1 into messages reply
$query_sel_last_id = "SELECT id FROM messages ORDER BY id desc LIMIT 1"; // select the last id
after that, you only need to insert to messages_reply, remember to plus the value
$query_sel_last_id + 1
EDIT: gordon's solution is better and simpler, LAST_INSERT_ID()

INSERT ...ON DUPLICATE KEY UPDATE when key is not always known?

I'm trying to update a record if the key is known else I want to insert it and get the inserted id, currently I have:
if(isset($data['applicationId']))
{
//update
$sql="
UPDATE myTable SET data='jsonstring' WHERE id = {$data['applicationId']}
";
}
else
{
//insert and get id
$sql="
INSERT INTO myTable SET data='jsonstring'
";
}
Is it possible to simplify the above to one query using INSERT ...ON DUPLICATE KEY UPDATE even when the key is not always known ?
I've tried this:
INSERT INTO myTable
(
id,
data
)
VALUES
(
?, # <- I may not know this!!
'jsonstring'
)
ON DUPLICATE KEY UPDATE
data = 'jsonstring'
Thanks for any suggestions.
Yes, you can do that, assumed id is your primary key and auto_increment. You will have two different queries, one if you know the applicationId and one when you not knowing it.
The first, when you know it:
INSERT INTO myTable
(
id,
data
)
VALUES
(
1337, # <- insert id
'jsonstring'
)
ON DUPLICATE KEY UPDATE
data = 'jsonstring';
And the one if the applicationId is unknown:
INSERT INTO myTable
(
id,
data
)
VALUES
(
NULL, # <- This will cause mysql to use a auto_increment value
'jsonstring'
)
ON DUPLICATE KEY UPDATE
data = 'jsonstring';
So you can conclude this to:
$sql="INSERT INTO myTable
(
id,
data
)
VALUES
(" .
isset($data['applicationId']) ? $data['applicationId'] : 'NULL'
.",
'jsonstring'
)
ON DUPLICATE KEY UPDATE
data = 'jsonstring';
";
But be aware of How can I prevent SQL-injection in PHP?
Happy coding
Please forgive because your question is not 100% clear. However, the concept I can tell is that you want to be able to ask more than 1 query on 1 sql statement. That can be done with a multi-query command. However, if you want some of your data from a query placed in your next query I do not think it will work. Link provided for multi_query
http://php.net/manual/en/mysqli.quickstart.multiple-statement.php
First, Simple update query will run. If it runs successfully, it will not go to if condition and your ID will be the one which was used in updating.
And, if that ID is not available (means update query fails, $Query will be false), so pointer jumps to if condition and insert the query. Now, new Inserted ID we can get.
$ID=$data['applicationId'];
$Query=mysql_query("UPDATE myTable SET data='jsonstring' WHERE id='$ID' ");
if(!$Query)
{
$InsertQuery=mysql_query("INSERT INTO myTable SET data='jsonstring'");
$ID=mysql_insert_id();
}
So, $ID will be your ID.(either updated or currently inserted)

Inserting data into multiple tables not functioning correctly

I have the following two tables
Table player:
player_id (int)(primary)
player_name (varchar)
player_report_count (int)
Table report:
report_id (int)(primary)
player_id
report_description
report_location
Firstly I ask the user for the player_name and insert it into the player database. From here the player is given an id.
Then I tried to grab the value of the players report count and increment the current value by one (which isn't working).
This is followed by grabbing the playerId from the player table and then inserting into the corresponding column from the report table (also does not work).
When I insert some values into the database, the names, description and report are added to the database however the playerID remains at 0 for all entries and the player_report_count remains at a consistent 0.
What is the correct way to make these two features function? And also is there a more efficient way of doing this?
<?php
$records = array();
if(!empty($_POST)){
if(isset($_POST['player_name'],
$_POST['report_description'],
$_POST['report_location'])){
$player_name = trim($_POST['player_name']);
$report_description = trim($_POST['report_description']);
$report_location = trim($_POST['report_location']);
if(!empty($player_name) && !empty($report_description) && !empty($report_location)){
$insertPlayer = $db->prepare("
INSERT INTO player (player_name)
VALUES (?)
");
$insertPlayer->bind_param('s', $player_name);
$reportCount = $db->query("
UPDATE player
SET player_report_count = player_report_count + 1
WHERE
player_name = $player_name
");
$getPlayerId = $db->query("
SELECT player_id
FROM player
WHERE player_name = $player_name
");
$insertReport = $db->prepare("
INSERT INTO report (player_id, report_description, report_location)
VALUES (?, ?, ?)
");
$insertReport->bind_param('iss', $getPlayerId, $report_description, $report_location);
if($insertPlayer->execute()
&& $insertReport->execute()
){
header('Location: insert.php');
die();
}
}
}
Main issue here is you are getting player details before inserting it. $getPlayerId will return empty result always.
Please follow the order as follows.
Insert player details in to player table and get payerid with mysql_insert_id. After binding you need to execute to insert details to the table.
Then bind and execute insert report .
Then update the player table by incrementing report count with playerid which you got in step 1.
Note : use transactions when inserting multiple table. This will help you to rollback if any insert fails.
MySQL Query will return result object. Refer it from here https://stackoverflow.com/a/13791544/3045153
I hope it will help you
If you need to catch the ID of the last insterted player, This is the function you need if you're using PDO or if it's a custom Mysql Class, you need the return value of mysql_insert_id() (or mysqli_insert_id()) and then directly use it in the next INSERT INTO statement

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