Mysql restrict on delete check - php

Question

I have a mysql database with restrict on delete setting.
I have this delete query:
if(isset($_POST['delete_id']))
{
$sqldelete="DELETE FROM tblAcqDetail WHERE ID=".$_POST['delete_id'];
$resultdelete = $conn->query($sqldelete);
}
How can I check if the query does delete anything or is restricted by mysql.
I need to run an update query (see below) only if the delete query works.
I tried:
if ($resultdelete->affected_rows> 0) {
// Escape user inputs for security
$status = mysqli_real_escape_string($link, $_POST['status']);
if(isset($_POST['status']))
{
$setsql="UPDATE tblInvoiceDetail SET TRANSFER = '0' WHERE ID='$status'";
$setresult = $conn->query($setsql);
}
}
I also tried
if ($resultdelete->num_rows > 0) {
And also :
if ($resultdelete) {
All of the above stop the update query from executing.

Answer 1

You can use mysqli_affected_rows().
From the docs:
Returns the number of rows affected by the last INSERT, UPDATE, REPLACE or DELETE query.
Note this is run on the connection object, not the result. So use $conn->affected_rows instead of $resultdelete->affected_rows.

Answer 2

Rather than passing $resultdelete in to mysqli_affected_rows you actually want to pass the DB link (returned by mysqli_connect) which will give you the number of rows affected by the previous query
$sqldelete="DELETE FROM tblAcqDetail WHERE ID=".$_POST['delete_id'];
$resultdelete = $conn->query($sqldelete);
if ($conn->affected_rows > 0) {// pass db link here
Read http://php.net/manual/en/mysqli.affected-rows.php

Answer 3

Your problem is you're referencing the wrong thing
if ($resultdelete->affected_rows> 0) {
But
$resultdelete = $conn->query($sqldelete);
only returns a boolean(emphasis mine).
Returns FALSE on failure. For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object. For other successful queries mysqli_query() will return TRUE
You want to reference the connection itself for how many rows were affected
if ($conn->affected_rows> 0) {

Answer 4

If condition should be
if ($conn->affected_rows> 0){}
not
if ($resultdelete->affected_rows> 0){}

Answer 5

You're using it wrong if ($resultdelete->affected_rows> 0) you're using num_rows() syntax with the >0 bit.
The connection is passed to the function and not from the result set.
RTM http://php.net/manual/en/mysqli.affected-rows.php
Object oriented style
int $mysqli->affected_rows;
Procedural style
int mysqli_affected_rows ( mysqli $link )
From the manual:
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* Insert rows */
$mysqli->query("CREATE TABLE Language SELECT * from CountryLanguage");
printf("Affected rows (INSERT): %d\n", $mysqli->affected_rows);
$mysqli->query("ALTER TABLE Language ADD Status int default 0");
/* update rows */
$mysqli->query("UPDATE Language SET Status=1 WHERE Percentage > 50");
printf("Affected rows (UPDATE): %d\n", $mysqli->affected_rows);
/* delete rows */
$mysqli->query("DELETE FROM Language WHERE Percentage < 50");
printf("Affected rows (DELETE): %d\n", $mysqli->affected_rows);
/* select all rows */
$result = $mysqli->query("SELECT CountryCode FROM Language");
printf("Affected rows (SELECT): %d\n", $mysqli->affected_rows);
$result->close();
/* Delete table Language */
$mysqli->query("DROP TABLE Language");
/* close connection */
$mysqli->close();
?>
Procedural style
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
if (!$link) {
printf("Can't connect to localhost. Error: %s\n", mysqli_connect_error());
exit();
}
/* Insert rows */
mysqli_query($link, "CREATE TABLE Language SELECT * from CountryLanguage");
printf("Affected rows (INSERT): %d\n", mysqli_affected_rows($link));
mysqli_query($link, "ALTER TABLE Language ADD Status int default 0");
/* update rows */
mysqli_query($link, "UPDATE Language SET Status=1 WHERE Percentage > 50");
printf("Affected rows (UPDATE): %d\n", mysqli_affected_rows($link));
/* delete rows */
mysqli_query($link, "DELETE FROM Language WHERE Percentage < 50");
printf("Affected rows (DELETE): %d\n", mysqli_affected_rows($link));
/* select all rows */
$result = mysqli_query($link, "SELECT CountryCode FROM Language");
printf("Affected rows (SELECT): %d\n", mysqli_affected_rows($link));
mysqli_free_result($result);
/* Delete table Language */
mysqli_query($link, "DROP TABLE Language");
/* close connection */
mysqli_close($link);
?>