Bigquery：将 SPLIT() 输出行分解为多列

Question

我在一列中有一个长字符串，需要将其分解为多行，然后拆分为多列。数据看起来像：（（a：10，b：20，c：test1）（a：40，b：50，c：test2）（a：60，b：70，c：test3））。当我应用 split 和 regexp_replace 时，我得到了类似的结果

选择 SPLIT(REGEXP_REPLACE(REGEXP_REPLACE(message, r'))',''), r'((','') ,')(') as msg FROM [mydataset.mytable]

输出：

味精
a:10,b:20,c:test1
a:40,b:50,c:test2
a:60,b:70,c:test3

我要找的是：
a b c
10 20 测试1
40 50 测试2
60 70 测试3

我再次使用 split 按 (,) 拆分行，但它只给我一行而不是 3。非常感谢您的帮助。

Answer 1

试试下面的例子

SELECT
  MIN(CASE WHEN name = 'a' THEN value END) AS a,
  MIN(CASE WHEN name = 'b' THEN value END) AS b,
  MIN(CASE WHEN name = 'c' THEN value END) AS c
FROM (
  SELECT
    message, msg, 
    REGEXP_EXTRACT(pair, r'(\w*):') AS name, 
    REGEXP_EXTRACT(pair, r':(\w*)') AS value
  FROM (
    SELECT message, msg, 
      SPLIT(msg) AS pair
    FROM (
      SELECT message, 
        SPLIT(REPLACE(REPLACE(message, '))',''), '((','') ,')(') AS msg
      FROM 
        (SELECT '((a:10,b:20,c:test1)(a:40,b:50,c:test2)(a:60,b:70,c:test3))' AS message),
        (SELECT '((a:12,b:22,c:test4)(a:42,b:52,c:test5)(a:62,b:72,c:test6))' AS message),
    )
  )
) 
GROUP BY message, msg

Answer 2

这是使用standard SQL 的替代解决方案（取消选中“显示选项”下的“使用旧版 SQL”框），它仍然相对冗长但需要较少的文本操作：

WITH MyTable AS (
  SELECT messages
  FROM UNNEST(['((a:10,b:20,c:test1)(a:40,b:50,c:test2)(a:60,b:70,c:test3))',
               '((a:12,b:22,c:test4)(a:42,b:52,c:test5)(a:62,b:72,c:test6))'])
    AS messages)
SELECT
  (SELECT value FROM UNNEST(message_parts) WHERE name = 'a') AS a,
  (SELECT value FROM UNNEST(message_parts) WHERE name = 'b') AS b,
  (SELECT value FROM UNNEST(message_parts) WHERE name = 'c') AS c
FROM (
  SELECT ARRAY(SELECT AS STRUCT
                 SPLIT(part, ':')[OFFSET(0)] AS name,
                 SPLIT(part, ':')[OFFSET(1)] AS value
               FROM UNNEST(SPLIT(message, ',')) AS part) AS message_parts
  FROM (SELECT message FROM MyTable,
          UNNEST(REGEXP_EXTRACT_ALL(messages, r'\(([^\(\)]+)\)')) AS message)
);