Regex title search against existing and deleted pages

Searches for both currently-existing and previously-deleted pages with a title matching a given regular expression.

Some warnings:
The expression is case-sensitive.  Prefix it with (?i) to make it insensitive.

It must double backslashes (so '\\b', not '\b', to match a word break, and '\\\\' to match a literal backslash).

It will not match parts of the title within the namespace (so e.g. 'k:' matches [[Looney Tunes Super Stars' Daffy Duck: Frustrated Fowl]] but not [[Talk:Physics]]).

SQL

SET @rx = '(?i)abdullah.*mehmood';
SELECT CONCAT(CASE page_namespace
                WHEN   -2 THEN 'Media:'             WHEN   -1 THEN 'Special:'
                WHEN    0 THEN ''                   WHEN    1 THEN 'Talk:'
                WHEN    2 THEN 'User:'              WHEN    3 THEN 'User talk:'
                WHEN    4 THEN 'Wikipedia:'         WHEN    5 THEN 'Wikipedia talk:'
                WHEN    6 THEN ':File:'             WHEN    7 THEN 'File talk:'
                WHEN    8 THEN 'MediaWiki:'         WHEN    9 THEN 'MediaWiki talk:'
                WHEN   10 THEN 'Template:'          WHEN   11 THEN 'Template talk:'
                WHEN   12 THEN 'Help:'              WHEN   13 THEN 'Help talk:'
                WHEN   14 THEN ':Category:'         WHEN   15 THEN 'Category talk:'
                WHEN  100 THEN 'Portal:'            WHEN  101 THEN 'Portal talk:'
                WHEN  108 THEN 'Book:'              WHEN  109 THEN 'Book talk:'
                WHEN  118 THEN 'Draft:'             WHEN  119 THEN 'Draft talk:'
                WHEN  446 THEN 'Education Program:' WHEN  447 THEN 'Education Program talk:'
                WHEN  710 THEN 'TimedText:'         WHEN  711 THEN 'TimedText talk:'
                WHEN  828 THEN 'Module:'            WHEN  829 THEN 'Module talk:'
                WHEN 2300 THEN 'Gadget:'            WHEN 2301 THEN 'Gadget talk:'
                WHEN 2302 THEN 'Gadget definition:' WHEN 2303 THEN 'Gadget definition talk:'
                ELSE CONCAT('{{ns:', page_namespace, '}}:')
              END,
              REPLACE(page_title, '_', ' ')) AS pagename,
              deleted
FROM (SELECT page_namespace, page_title, 0 AS deleted
      FROM page
      WHERE REPLACE(page_title, '_', ' ') RLIKE @rx
      UNION
      SELECT DISTINCT ar_namespace, ar_title, 1
      FROM archive
      WHERE REPLACE(ar_title, '_', ' ') RLIKE @rx) sq;

SQL

Checking query status...