How to get max from sql in php - php

So I'm buidlign a website currently and there is a form connected to a database.
You can put some information in the form and it will send you an email and will put the information into the database.
So... I wanted it also ad a number into the database and auto count the number. This lead me thinking.... If I use max and just do +1 and insert that, Jobs done right!!.... Well no....
The code isn't working for me and I have no idea where to start...
This is al I made and when I do this I only get 1 as an answer.
$sql2 = "SELECT MAX(Nummer) FROM Leerling" ;
$sql3 = $sql2 + 1;
echo $sql3;
The insert statement is
"INSERT INTO Leerling(Nummer, Naam, Klas, Email, Bericht) VALUES ('" . $sql3 . "', '" .$naam. "', '" .$klas. "' , '" .$email. "', '" .$bericht. "');" ;
Which only inserts 0 into the database on the place where it says $sql2. I'm totaly clueless so any help is much needed help.
(Don't mind my English if it's not correct >.< I'm Dutch)

You should use MySQL AUTO_INCREMENT
Your column Nummer will increase its value every time you insert a new row and no need for calculate the MAX value to increase Nummer for the new row

Related

mysql query inserting data multiple times

I have a table log_Data where i log searched keyword that user enter. I am facing an issue that mysql query is inserting data multiple time. query is super simple INSERT INTO TABLE_NAME (id, keyword, date_adde) ... but if user enter some word... the query will insert it and after some seconds it will insert again and sometimes it insert same record for 4 5 times.
How can i limit and make this insertion more accurate so i can avoid duplication and get better and more accurate search reports.
EDIT
inside my controller i have:
if(isset($this->request->get['search']) && $this->request->get['search'] != ' '){
$search_log = array(
'keyword' => $this->request->get['search'],
'source' => '0', //0 for website and 1 for application
'total_result' => $product_total
);
$this->model_catalog_product->searchLog($search_log);
}
Inside my Model i have:
public function searchLog($data){
$query = $this->db->query("INSERT INTO search_log SET keyword = '" . $this->db->escape($data['keyword']) . "', record = '" . (int)$data['total_result'] . "', customer_id = '" . (int)$this->customer->getId() . "', source = '" . (int)$data['source'] . "', ip = '" . $this->db->escape($this->request->server['REMOTE_ADDR']) . "', date_added = NOW()");
}
attached an image where a customer searched for heel 'highlighted with black' is inserted 7 times with difference in few seconds... the customer originally searched for 1 time only... same as for other words as well...
first, check your code. Secound make a unquiq key:
md5 ( keyword + date + hour )
try to avoid duplicate in any form by adding session protection add hidden input call it doupleprotection it is value come from randomization like rand(1000, 10000000000) or md5(time()) then save this value in session like $_SESSION['doubleprotection']
Afer submit form and before inserting in database compare input value with $_SESSION['doubleprotection'] , if equal do query then give $_SESSION['doubleprotection'] new value from rand(1000, 10000000000)
if input value and $_SESSION['doubleprotection'] not equal stop query

Trigger to delete table and then insert value with Mysql

How could i do a query with php and mysqli, to remove an entire table and then add new I have a form where data is received, but before adding the new data, I want to remove all data from table.
$oConni is my connection string
$cSQLt = "TRUNCATE TABLE approved";
$cSQLi = "INSERT INTO approved (ID_STUDENT, YEAR, APPROVED)
VALUES (
'" . $_POST['NSTUDENT'] . "',
'" . $_POST['YEAR'] . "',
'YES'
)";
$oConni->query($cSQLt);
$oConni->query($cSQLi);
You can remove everything from a table with MySQL by issuing a TRUNCATE statement:
TRUNCATE TABLE approved;
.. which usually is the same as
DELETE FROM approved;
.. but there are a few small differences, which you can read about in the documentation.
In the code you've pasted, please use prepared statements to avoid a sql injection attack. Never use unfiltered POST-data directly in a query!
If you want to do this as a trigger, we'll need to know a bit more about your data handling. Issuing a TRUNCATE before a INSERT will usually lead to only one row being available in the table, which seems like a weird use case for actually using a table.
You could use TRUNCATE TABLE and then your next query:
$cSQLt = "TRUNCATE TABLE CALIFICA_APTO";
$cSQLi = "INSERT INTO approved (ID_STUDENT, YEAR, APPROVED)
VALUES (
'" . $_POST['NSTUDENT'] . "',
'" . $_POST['YEAR'] . "',
'YES'
)";
$Connect->query($cSQLt);
$Connect->query($cSQLi);
If your looking to remove all of the data from a table you should use TRUNCATE:
TRUNCATE TABLE approved
Then you can do your SQL statement.
NOTE: This will delete all data from the table, so be careful! Also, your database user must have the ability to truncate tables.

Counter in mysql doesn't work

I'am trying to implement a "most popular searches" function on a web site using a simple counter. The idea is that the first time a search is made, the query is stored in a special table. After that the count number increments by one every time that same search is made. I think I do exactly as I should but the code doesn't seem to work. The count value stays on NULL in the table. Here's my code. "Searchny" is the table where I store the searches. Any pointers much appreciated!
$search_result = mysql_query("SELECT * FROM searchny WHERE sok='$sokt'");
if(mysql_num_rows($search_result) == 0 ) {
$sql = "INSERT INTO searchny (sok, dt) VALUES ('" . $sokt . "', NOW());";
mysql_query($sql);
}
else {
mysql_query("UPDATE searchny SET count = count+1 WHERE sok='$sokt'");
}
Probably your count column is NULL by default and every count+1 doesn't make it any less NULL. Try either setting default value of one or explicitly set it to one in INSERT.
Your code has no mistake, so the problem isn't the code.
Is your value NULL or 0 ?
If it is NULL, change
INSERT INTO searchny (sok, dt) VALUES ('" . $sokt . "', NOW());
to
INSERT INTO searchny (sok, dt, count) VALUES ('" . $sokt . "', NOW(), 0);
Your problem is most likely that count is NULL. Anything added to NULL is NULL.
Try this query:
SELECT NULL + 1
The result will be:
NULL
You could set your default value for the count field to 0 instead.
However, here's a simpler way to implement this. Note that I've excluded the date field because I don't know what the requirements for the date are:
Table searchny:
---------
sok
count
---------
primary_key (sok)
Then do it all in one statement:
INSERT INTO searchny (sok, count) VALUES ($sokt, 1)
ON DUPLICATE KEY UPDATE count = count + 1
If it's a new sok value, then a new row is inserted and the count is set to 1. If the sok value already exists, then the record's count is incremented by 1.

php mysql save mysql with for loop

TABLE:
09:00 -- id_timeslot = 1
09.15 -- id_timeslot = 2
09.30 -- id_timeslot = 3
09.45 -- id_timeslot = 4
10.00 -- id_timeslot = 5
PHP MYSQL:
for($i=0; $i<=2; $i++) {
$mysqli->query("INSERT INTO bookslot(id_timeslot, id_member, b_ref, id_doctor, status)
VALUES ('" . ++$id_timeslot . "', '" . $id_member . "', '" . $b_ref . "', '" . $id_doctor . "', 1)" )
}
I want the data to be saved twice and increment the id_timeslot.
The above code working fine, but when save cliked. it didnt pick up the right id_timeslot?
for example: if user click on id_timeslot:1, soon it save to database the id_timeslot starts from 2 instead of id_timeslot 1?
if user click on id_timeslot:1, soon it save to database the id_timeslot starts from 2 instead of id_timeslot 1?
This is because you're using a pre-increment rather than a post-increment. If $id_timeslot is 1 before entering the loop, the value of ++$id_timeslot is 2, so the first generated query is:
"INSERT INTO bookslot(id_timeslot, id_member, b_ref, id_doctor, status)
VALUES ('2', '$id_member', '$b_ref', '$id_doctor', 1)"
If the id_timeslot column is supposed to be an ID for the bookslot record, the best approach is to declare it with the AUTO_INCREMENT attribute and don't insert values for that column:
-- run just once in some MySQL client
ALTER TABLE bookslot MODIFY id_timeslot INT UNSIGNED PRIMARY KEY AUTO_INCREMENT;
// in PHP
$stmt = "INSERT INTO bookslot(id_member, b_ref, id_doctor, status)
VALUES ('$id_member', '$b_ref', '$id_doctor', 1)";
When using double quoted strings, you don't need to concatenate variables. Compare the above statement with your own.
If id_timeslot isn't a unique ID, then you can simply switch to post-increment.
$stmt = "INSERT INTO bookslot(id_timeslot, id_member, b_ref, id_doctor, status)
VALUES (" . $id_timeslot++ . ", '$id_member', '$b_ref', '$id_doctor', 1)";
This may or may not be a correct approach for various other reasons. Without knowing more about the schema, it's impossible to say.
Off Topic
Depending on where the values for $id_member, $b_ref $id_doctor originate, your script could be open to SQL injection. Rather than inserting values directly into the string, use a prepared statement. MySQLi supports them, as does PDO, which is simpler to use. New code should use PDO, and old code should get updated over time.
You have to fetch last id_timeslot from database and then increase it PHP during inserting.

sql insert and update question

I have a form which to insert data into a database. This form takes the content of the fields, and then displays the result page showing the entered information in context. There is a link on this page to edit the user info, which go back to the previous form. Obviously, I do not want duplicate records inserted. Is there an easy way to use an update statement if a record already exists? I am doing this with ajax and php.
Take a look at:
INSERT ... ON DUPLICATE: http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html
REPLACE INTO: http://dev.mysql.com/doc/refman/5.0/en/replace.html
INSERT ... ON DUPLICATE will allow you to issue an UPDATE query when a UNIQUE INDEX or PRIMARY KEY is matched.
REPLACE works exactly the same, but if the row is found, the old row is deleted prior to inserting a new one. When using cascading deletes, this is especially something to take into account!
MySQL supports the addition of ON DUPLICATE KEY UPDATE to an INSERT statement, which should do what you want.
Assuming you have a field like 'username' or 'email', you could make use of that field to check if a record already exists, if it does, update it.
$res = mysql_query("SELECT primary_key FROM my_table WHERE `email` = '" . mysql_real_escape_string($email) . "'");
if($row = mysql_fetch_array($res))
{
// Record exists, update it
$q = "UPDATE my_table SET `username` = '" . mysql_real_escap_string($username) . "' WHERE primary_key = " . (int) $row['primary_key'];
}
else
{
// Record doesn't exist, insert
$q = "INSERT INTO my_table(username, email) VALUES('" . mysql_real_escape_string($username) . "', '" . mysql_real_escape_string($email) . "');";
}
In the above example I assume you have a primary key field that's an integer (primary_key).
You should consider using an ORM like http://www.ezpdo.net/blog/?p=2
Plain SQL in web applications should only be used if absolutely neccessary, alone for security reason, but also to avoid problems like yours.

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