从字符串中删除空值

Question

我想用language_id＆＃39; us＆＃39;来显示已翻译的名称和说明。和＆＃39; ru。我的问题是如何删除空值？

SELECT DISTINCT CASE WHEN LANGUAGE_ID = 'US' THEN COALESCE(TO_CHAR(TRANSLATED_NAME), ' ')
       END AS PRODUCT_NAME_US,
       CASE WHEN LANGUAGE_ID = 'US' THEN INITCAP(CONCAT(SUBSTR(TRANSLATED_DESCRIPTION, 1, 30), '...'))
       END AS PRODUCT_DESC_US,
       CASE WHEN LANGUAGE_ID = 'RU' THEN COALESCE(TO_CHAR(TRANSLATED_NAME), ' ')
       END AS PRODUCT_NAME_RU,
       CASE WHEN LANGUAGE_ID = 'RU' THEN INITCAP(CONCAT(SUBSTR(TRANSLATED_DESCRIPTION, 1, 30), '...'))
       END AS PRODUCT_DESC_RU
FROM PRODUCT_DESCRIPTIONS;

Answer 1

我怀疑你想要这样的东西：

SELECT PRODUCT_ID,
       MAX(CASE WHEN LANGUAGE_ID = 'US' THEN COALESCE(TO_CHAR(TRANSLATED_NAME), ' ')
           END) AS PRODUCT_NAME_US,
       MAX(CASE WHEN LANGUAGE_ID = 'US' THEN INITCAP(CONCAT(SUBSTR(TRANSLATED_DESCRIPTION, 1, 30), '...'))
           END) AS PRODUCT_DESC_US,
       MAX(CASE WHEN LANGUAGE_ID = 'RU' THEN COALESCE(TO_CHAR(TRANSLATED_NAME), ' ')
           END) AS PRODUCT_NAME_RU,
       MAX(CASE WHEN LANGUAGE_ID = 'RU' THEN INITCAP(CONCAT(SUBSTR(TRANSLATED_DESCRIPTION, 1, 30), '...'))
           END) AS PRODUCT_DESC_RU
FROM PRODUCT_DESCRIPTIONS
GROUP BY PRODUCT_ID; -- whatever each row defines

这为每个产品做了明确的聚合（当然使用适当的id），将英语和俄语翻译放在适当的列中。