"将 CASE 语句列添加到现有 GBQ 表"

Question

假设我有一个 GBQ 表：

SELECT 
'city_A' AS city,
15 AS score
UNION ALL
SELECT 
'city_A' AS city,
17 AS score
UNION ALL
SELECT 
'city_B' AS city,
8 AS score

Answer 1

你想在这里更新。 假设您的表已经有一个iso_code列，然后使用：

UPDATE yourTable
SET iso_code = CASE city WHEN 'city_a' THEN 'LA'
                         WHEN 'city_b' THEN 'PH' END
WHERE city IN ('city_a', 'city_b');

话虽如此，如果 BigQuery 支持，您的iso_code列真的感觉它可能是一个生成的列。