I'm quite new to coding mysqli in general and have a problem I can't solve on my own:
I have created an insert, delete and update page. Insert and delete new data in the database table works fine, but when I try to update an existing record, the query somehow deletes the content of other fields in my table row at random.
I have only used the sql sql = "UPDATE xxx SET name='$name' WHERE id='$id"; etc.
What am I doing wrong?
You've got an issue with your SQL.
This: sql = "UPDATE xxx SET name='$name' WHERE id='$id"
Should be: sql = "UPDATE xxx SET name='$name' WHERE id = $id" <=== no quote before id
Integer values should not have quotes around them.
Either that or: sql = "UPDATE xxx SET name='$name' WHERE id = '$id'", if your id column is not an integer
you didn't close the single quote in the WHERE clause.
id is an integer value, so you shouldn't need the quotes at all:
WHERE id=$id
Related
Here, update chooses bal(for balance) column of register table whose is to be changed to difference of bal and the value in variable $tax for only the row saisfying the condition. It's not working in following code.How to do it?
$query3 = mysql_query('update table register set bal=bal-'.$tax.' where name='.$user.')' , $connection);
You are using in an incorrect way.
Try this:
$query3 = mysql_query("update table register set bal=(bal-$tax) where name='$user'" , $connection);
It seems, there is extra ')' after user, that hasn't '('
I'm using $id = mysqli_insert_id($connection); to get the last inserted id, but in case if it updates any record in the table, it returns 0 as last inserted id.
Is there any way to handle this?
I want to get id each time weather it's inserting or updating.
Thanks
Edit
I need this id to be used for inserting data into table2
id from tab1
put data into tab2 where id from tab1 is FK
and most important, I'm not using the update with where clause
Here is my code that I'm using
$val = utf8_encode($val);
mysqli_set_charset($connection, 'utf8');
mysqli_query($connection, "SET NAMES 'utf8'");
mysqli_query($connection, "SET FOREIGN_KEY_CHECKS = 0;");
$sql = "INSERT INTO leaks($insert) VALUES($val)";
$sql .= " ON DUPLICATE KEY UPDATE `url` = '".mysqli_real_escape_string($connection,$data['url'])."';";
mysqli_query($connection, ($sql))or die(mysqli_error($connection)."<br />".print($sql));
$id = mysqli_insert_id($connection);
$proofs['leaks_id'] = $id;
mysqli_query($connection, "SET FOREIGN_KEY_CHECKS = 0;");
print_r($id);
$this->insertProofs($connection, $proofs);
connection::close_connection($connection);
Please note down that $this->insertProofs($connection, $proofs); inserts data to table2 on the base of key passed to it
On INSERT
After executing an INSERT query, using mysqli_insert_id() is absolutely fine.
On UPDATE
Depending on your update, you;
Would know the id's you're updating
Know the criteria to search for the id's from the update.
For example, if your UPDATE was something like;
UPDATE `foo` SET `x`='y' WHERE `a`='b'
You can then run
SELECT `id` FROM `foo` WHERE `a`='b'
to fetch the updated id's.
Edit
I see you're using ON DUPLICATE KEY UPDATE.
You can modify your query to become (assuming id is the primary auto_increment key)
ON DUPLICATE KEY UPDATE
`url` = '".mysqli_real_escape_string($connection,$data['url'])."',
id = LAST_INSERT_ID(id)
Then you can use mysqli_insert_id() regardless of if it was an UPDATE or INSERT
For example, if I run (with a record of id=2 exists; so we'll update);
INSERT INTO foobar (id, foo) VALUES (2, 'bar') ON DUPLICATE KEY UPDATE foo = 'baz', id = LAST_INSERT_ID(id);
SELECT LAST_INSERT_ID();
The output is 2, as that was the last insert id.
This query had previously worked, now when it is run again we get Unknown Column in field list error.
The query works well if we do not use variables and set raw data. The columns match those in the database.
$update_order_id = "UPDATE order_tbl SET o_process=$process, o_payment=$payment, o_paymentType=$paymenttype WHERE o_id=$orderid AND o_active='1'";
You need wrap single quotes for the values in the query as
o_process='$process'
etc
So the query will be as below. For string values its necessary.
$update_order_id = "UPDATE order_tbl
SET o_process='$process',
o_payment='$payment',
o_paymentType='$paymenttype'
WHERE o_id= '$orderid' AND o_active='1'";
You might need to surround your variables with quotes, only integer columns doesn't need quotes.
$update_order_id = "UPDATE order_tbl SET o_process='$process', o_payment='$payment', o_paymentType='$paymenttype' WHERE o_id='$orderid' AND o_active='1'";
Does it work for anyone? :P
I can properly get insert_id while inserting, but not on update. Of course contactsId column is AUTO_INCREMENT.
Whole code:
<?php
$mysqli = new mysqli('localhost', [USER], [PASSWORD], [DB]);
$mysqli->set_charset("utf8");
$query = 'INSERT INTO contacts (contactsName) VALUES ("Mariola")';
$result = $mysqli->query($query);
echo $mysqli->insert_id . '<br />';
$query = 'UPDATE contacts SET contactsName = "Mariola" WHERE contactsId = 289';
$result = $mysqli->query($query);
echo $mysqli->insert_id;
Output:
1514
0
I HAVE record with id 289, and update works fine.
This behavior is described very clear in the document.
mysqli::$insert_id -- mysqli_insert_id — Returns the auto generated
id used in the last query
If the last query wasn't an INSERT or UPDATE statement or if the
modified table does not have a column with the AUTO_INCREMENT
attribute, this function will return zero.
From MySQL documentation on LAST_INSERT_ID():
If expr is given as an argument to LAST_INSERT_ID(), the value of the argument is returned by the function and is remembered as the next value to be returned by LAST_INSERT_ID(). This can be used to simulate sequences:
Create a table to hold the sequence counter and initialize it:
mysql> CREATE TABLE sequence (id INT NOT NULL);
mysql> INSERT INTO sequence VALUES (0);
Use the table to generate sequence numbers like this:
mysql> UPDATE sequence SET id=LAST_INSERT_ID(id+1);
mysql> SELECT LAST_INSERT_ID();
The UPDATE statement increments the sequence counter and causes the next call to LAST_INSERT_ID() to return the updated value. The SELECT statement retrieves that value. The mysql_insert_id() C API function can also be used to get the value. See Section 20.6.7.37, “mysql_insert_id()”.
Maybe something like this will work:
$query = 'UPDATE contacts SET id = LAST_INSERT_ID(id), contactsName = "Mariola" WHERE contactsId = 289';
How can I increment an int in a cell of a MySQL database? I know that auto-increment is no use because I never want to add a new row, just update an existing one. I'm currently using this (POST var used for clarify, is verified in the real code):
$columnToUpdate = 'type'.$_POST['voteid'];
$query = "UPDATE myTable $columnToUpdate = $columnToUpdate+1 WHERE id=1;";
if(!mysql_query($query)) {
echo json_encode(array('success' => false, 'message' => 'Update failed: '.mysql_error()));
exit;
}
In the database I have 6 fields, id, type1, type2, type3, type4, type5, and a single row with id set to 1. The intention is to recieve a number (1-5), and build a reference to the correct column before updating the field. That results in Update failed: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=type4+1 WHERE id=1' at line 1, so I guess it's not getting the field value out properly before it increments.
Once this is working I'm also going to need to decrement a field in the same way, unless its value is 0. So for bonus points, can I do all this in one query or would it be better to split it up?
I think you've missed the keyword 'SET' from your query - try
$query = "UPDATE myTable SET $columnToUpdate = $columnToUpdate+1 WHERE id=1;";
Edit:
To do the "decrement unless it's zero" you could use something like:
UPDATE myTable SET $columnToUpdate =
CASE $columnToUpdate
WHEN 0 THEN 0
ELSE $columnToUpdate - 1
END CASE
WHERE id=1;`
For bonus points, to decrement:
$query = "UPDATE myTable SET '$columnToUpdate' = '$columnToUpdate'-1 WHERE id=1 AND '$columnToUpdate' > 0";
Besides the injection issues, it seems as if your workflow may need some work. Are you sure you want to choose the column that will be updated based on POST variable? It seems like you would specify the column and use the variable to find the record that needs to be updated:
IE:
"UPDATE myTable SET votes=votes+1 WHERE id=$post_variable;"
Again you should send the variable as a parameterized query to protect yourself from SQL injection.