Премахване на уеб адреса от текстов низ

Ако URL част съществува само веднъж в текста, следното трябва да работи.

MySQL Решение:

select concat( @pss:=substring_index( txt, 'http://', 1 ), 
               substring( @ss:=substring_index( txt, 'http://', -1 ), 
                          if( (@l:=locate( ' ', @ss )) > 0, @l+1, 0 ) ) 
       ) as txt
from (
  select 'This is a test http://t.co/aBc689XYz' as txt
  union all
  select 'Have a nice http://t.co/vZ754PlkuI day'
  union all
  select 'This worked http://sqlfiddle.com/#!2/d41d8 perfectly on sql fiddle'
) records
;

Резултати :

+-------------------------------------+
| txt                                 |
+-------------------------------------+
| This is a test                      |
| Have a nice day                     |
| This worked perfectly on sql fiddle |
+-------------------------------------+

Демо @ MySQL 5.5.32 Fiddle