Question

I need to retrieve a field, only if is not empty:

I have a table with: counter(primary),id (this is the same for the same page), text, language and other fields: i have the id and the language.

I need to search the text in that language, and if it’s empty I need the text in english.
example:
– 0,1,hello,eng
– 1,1,ciao,ita
In this case I need to retrieve “ciao”, but if it’s empty I need “hello”.

How can I?

Answer 1

Well, I guess you could just get the Italian (if not empty) and the English and order with Italian first (if any):

SELECT
    text
FROM
    <table>
WHERE
    id = <page-id>
  AND (
      (
        language = '<preferred-language-to-retrieve>'
          AND
        text IS NOT NULL
      )
    OR
      language = '<fallback-language>'
  )
ORDER BY
    language = '<preferred-language-to-retrieve>' DESC
LIMIT 1

(untested)

With substituted values for Italian with English fallback for page ID = 75 (assuming table is named l10n):

SELECT
    text
FROM
    l10n
WHERE
    id = 75
  AND (
      (
        language = 'ita'
          AND
        text IS NOT NULL
      )
    OR
      language = 'eng'
  )
ORDER BY
    language = 'ita' DESC
LIMIT 1