String truncate on length, but no chopping up of words allowed

Question

I want to limit a string field length in MYSQL on a certain length, but I don\'t want any chopping up of words to occur.

When I do:

SELECT SUBSTRING(         


        

Answer 1

@Andriy M. I liked very much your answer :) Anyway I find on my db it works better if you change lines 2 and 3 like this:

SELECT
  IF(LENGTH(str)<=@len,str,LEFT(str, cutpos)) AS str1,
  IF(LENGTH(str)<=@len,'',SUBSTRING(str, cutpos + 1)) AS str2
FROM (
  SELECT
    @str AS str,
    @len - IFNULL(NULLIF(LOCATE(' ', REVERSE(LEFT(@str, @len))), 0) - 1, 0) AS cutpos
  FROM @table
) s

Don't know if it's my fault or what, but the other way it sometimes truncated strings on the first letter when their length was <@len, i.e. "First s" - "tring" instead of "First" "string" when @len=13

I post you a working example:

CREATE TABLE `test` (
  `sometext` varchar(65)
);

INSERT INTO `test` (`sometext`) VALUES
('Firs strin'),
('Alll right'),
('third string'),
('fourth string'),
('a longer example string'),
('Supercalifragilisticexpialidocious');

SELECT
  IF(LENGTH(str)<=12,str,LEFT(str, cutpos)) AS str1,
  IF(LENGTH(str)<=12,'',SUBSTRING(str, cutpos + 1)) AS str2
FROM (
  SELECT
    sometext AS str,
    12 - IFNULL(NULLIF(LOCATE(' ', REVERSE(LEFT(sometext, 12))), 0) - 1, 0) AS cutpos
  FROM test
) s

And here is a not-working example using your original code:

SELECT
  LEFT(str, cutpos) AS str1,
  SUBSTRING(str, cutpos + 1) AS str2
FROM (
  SELECT
    sometext AS str,
    12 - IFNULL(NULLIF(LOCATE(' ', REVERSE(LEFT(sometext,12))), 0) - 1, 0) AS cutpos
  FROM test
) s

I'm not sure if it's a utf8 issue, or I just misinterpreted your code, or what else...