Select a portion from a MySQL Blob Field

14
votes

I have a table containing lots of data and one of them is a blob. I some times needs to look into this blob for data using PHP.

I do:

select `desc` from table where `desc` like '%Nam rhoncus%';

this return the entire data but I don't need it

So if my description is like this:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. In a tempor velit. Integer sit amet ligula nibh, eu rutrum ante. Mauris cursus, neque eu ultrices pulvinar, purus purus fermentum libero, in eleifend tortor orci quis lectus. Cras luctus nunc ac tortor laoreet eu iaculis libero consectetur. Maecenas iaculis facilisis libero sodales auctor. Donec gravida interdum vehicula. Suspendisse vitae massa eget arcu condimentum mattis. Fusce ut ligula ante, nec placerat felis. Maecenas vel nunc nibh, ut luctus urna. Nunc eu lectus a orci iaculis volutpat eget a lorem. Nunc lobortis porttitor tempor. Nulla ipsum neque, volutpat in viverra sit amet, pharetra non tortor. Phasellus at leo pellentesque nunc ultrices euismod.

Nulla ullamcorper scelerisque leo, eu consequat risus fringilla id. Nulla facilisi. Cras sit amet sem a diam molestie dignissim. Duis interdum, sapien quis laoreet bibendum, dui turpis imperdiet magna, id auctor metus velit sollicitudin dolor. Integer blandit, turpis eget interdum commodo, ante nisl laoreet dui, ac congue purus dui quis nisl. Etiam blandit eleifend tortor at egestas. Vestibulum euismod orci ac nibh consectetur feugiat. Praesent ac libero quam. Morbi elit nulla, gravida ac blandit eu, bibendum vitae lacus. In facilisis pellentesque ipsum aliquam auctor. Nam rhoncus, purus eget fringilla ullamcorper, mauris tellus fermentum lectus, ut tempus tellus arcu vel dolor. Suspendisse eros augue, tincidunt sit amet luctus et, auctor id turpis. Praesent consequat velit ut arcu convallis sodales. Proin pulvinar varius erat, id consequat orci varius sed.

An I am looking for: Nam rhoncus I want to get the first occurence like:

...m auctor. Nam rhoncus, purus eg...

2
phpmysqlsql
did you forget to escape the desc with `? – Book Of Zeus

2 Answers

15
votes

This query:

SELECT 
  CONCAT(
    '...', 
    SUBSTR(`description`, 
      LOCATE('Nam rhoncus', `description`) - 10, 
      (LENGTH('Nam rhoncus') + 20)), 
    '...') AS `description`
FROM table 
WHERE `description` LIKE '%Nam rhoncus%';

(I broke it down like this so it's easier to read)

this will output:

...m auctor. Nam rhoncus, purus eg...

So in your PHP you can do:

<?php
define('CHAR_LEFT', 10);
define('CHAR_RIGHT', 10);
// db stuff
$search = mysql_real_escape_string($search_var);
$query = "SELECT CONCAT('...', SUBSTR(`description`, LOCATE('" . $search . "', `description`) - " . CHAR_LEFT . ", (LENGTH('" . $search . "') + " . (CHAR_LEFT + CHAR_RIGHT) . ")), '...') AS `description` FROM table WHERE `description` LIKE '%" . $search . "%';";
// then your request

NOTE: Ill be careful using mysql reversed words, this is why I use description instead.

0
votes

Something like the following should do what you need:

SELECT
    SUBSTR(description, INSTR(description, 'Nam rhoncus'), LENGTH('Nam rhoncus')) matchStr
FROM
    testTable
WHERE
    description like '%Nam rhoncus%'
;