Getting just the number of rows using Mysqli and PHP - php

Question

I want to get how many (possibly 0) times a particular number occurs in a particular column. I set the number in $contact_client_ID then do the SELECT query below.
$sql = "SELECT * FROM t_contacts WHERE contact_client_ID ='$contact_client_ID'";
$result=(mysqli_query($link, $sql));
$count_result= mysqli_num_rows($result);
echo "contact client ID $contact_client_ID xxxxx $count_result";
Instead of $count_result containing the number I want, it contains a result made up of the number I want and the contact_client_ID joined together and the result doesn't seem to be usable as a number in any following code.
So, if $contact_client_ID = 50 and there are 2 occurrences of it in the table, the output I get is:
contact client ID 50 xxxxx 250
I've looked at the manuals and examples all over the place (including here) and I can't see what I'm doing wrong.

Answer 1

There are multiple ways of doing this, more precisely you have the option, to either do the count in PHP, or make your SQL server do the counting and just return the number:
Do it in PHP:
What it requires is: - fetch all data; -make a counter variable; - loop trough the data, for each loop increase counter +1
For small tables you can use PHP, for bigger ones I advice doing it on the SQL, since for PHP to count it it must fetch all the data.
$counter=0;
$query = "SELECT * FROM t_contacts WHERE contact_client_ID ='$contact_client_ID";
$res = $con->query($query);
while ($row = $res->fetch_assoc()) {
$counter++;
}
Do it in SQL
Now the smarter way would be to do it on the SQL server ,as it would handle the load better;
I would say what /u/Adaleni wrote is pretty close to what I would use:
$sql = "SELECT count(contact_client_ID) as total FROM t_contacts WHERE contact_client_ID ='$contact_client_ID'";
$result=mysqli_query($link, $sql);
$count_result= mysqli_fetch_row(result);
echo "contact client ID $contact_client_ID xxxxx $count_result[0]['total']";
Lets just describe what he does:
we use COUNT() function in SQL, this makes the server count the number of occurances of contact_client_ID and then make (in the result) a new variable called "total"
we execute the query and get the result
We use mysqli_fetch_rowm this function gets the result row as an enumerated array
then we access that array (as we know its only 1 item, we accessed index 0) and we print the variable total which we made in step 1 - $count_result[0]['total']

Answer 2

Try this
/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT * FROM t_contacts WHERE contact_client_ID ='$contact_client_ID")) {
printf("Select returned %d rows.\n", $result->num_rows);