Query works in sql but not in php

Question

I have the following query that works right in sql

SELECT *
FROM `dsrequest`
WHERE dsrequeststatusID NOT IN ('4', '5', '6')
AND CASE
WHEN ('Κ' REGEXP '^[0-9]+$')  THEN
dsrequestClientAfm LIKE 'Κ%'
ELSE
( dsrequestClientFirstName LIKE 'Κ%' OR  dsrequestClientLastName LIKE 'Κ%' OR  dsrequestClientEmail LIKE 'Κ%'  )
END

but when I place it in the php using variable instead of 'K' gives me wrong set of results, that is it seems that where part doesn't work at all. I get records that dsrequestStatusID are 4, which should not be the case.

Here is the query that I use in php:

$this->db->query("SELECT *
FROM `dsrequest`
WHERE dsrequeststatusID NOT IN ('4', '5','6')
AND CASE
WHEN ('$searchString' REGEXP '^[0-9]+$')  THEN
dsrequestClientAfm LIKE '$searchString%'
ELSE
( dsrequestClientFirstName LIKE '$searchString%' OR  dsrequestClientLastName LIKE '$searchString%' OR  dsrequestClientEmail LIKE '$searchString%'  )
END");

Anyone can spot the mistake?

UPDATE:

After the suggestion I manage to print the query, and it is the same

SELECT * FROM `dsrequest` 
WHERE dsrequeststatusID NOT IN ('4', '5','6') 
AND CASE 
WHEN ('Κ' REGEXP '^[0-9]+$') THEN 
dsrequestClientAfm LIKE 'Κ%' 
ELSE 
( dsrequestClientFirstName LIKE 'Κ%' OR dsrequestClientLastName LIKE 'Κ%' OR dsrequestClientEmail LIKE 'Κ%' ) 
END

Anyone can spot any difference that I can't? Is the regular expression the issue? Did they have any difference between sql and php?

Answer 1

Sorry for putting you all of you in trouble. Problem was elsewhere with my codeigniter code, not with the query. As soon as I fixed that, query now works like a charm.