從字符串中刪除空值

Question

我想用language_id'us'和'ru'顯示翻譯后的名稱和描述。 我的問題是如何刪除空值？

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

我懷疑您想要這樣的東西：

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

這會對每種產品進行明確的匯總（當然使用適當的ID），並將英語和俄語翻譯放在適當的列中。