Wordpress php get result from sql where special character - php

Question

I have this code
$ntimes = $wpdb->get_var("SELECT Count(*) FROM wp_comp_review_list where email = $key->email");
What I was trying to do is count the number of emails where email = "sample#gmail.com". Wherein the email to compare is generated from another foreach loop.
I am having the following error:
"WordPress database error: [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 '#gmail.com' at line 1]"
I tried the by comparing names that has spaces. I got the same error because of the space.
Any tips on how to use WHERE with special characters?

Answer 1

An email is a string so you should use quotes, where email = '$key->email' though you're also open to SQL injection, if not it's better safe then hacked..
So you should use prepared statements instead using prepare().
<?php
$results = $wpdb->get_results(
$wpdb->prepare('
SELECT Count(*)
FROM wp_comp_review_list
WHERE email = %s',
[
$key->email
]
)
);
This should also work using esc_sql(), though avoid when you can:
<?php
$email = esc_sql($key->email);
$wpdb->get_var("
SELECT Count(*)
FROM wp_comp_review_list
WHERE email = '{$email}'"
);
?>

Answer 2

Use this :
$ntimes = $wpdb->get_var("SELECT Count(*) FROM wp_comp_review_list where email = '$key->email'");
Since your $key->email has space, it is no more a single word and next thing after space is considered as SQL command (which is it not)

Answer 3

You miss quote '' from the condition:
$ntimes = $wpdb->get_var("SELECT Count(*) FROM wp_comp_review_list where email = '$key->email'");