Bigquery unnest 和 pivot 列

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英文:

Bigquery unnest and pivot column

问题

我有一个在BigQuery中格式如下的非常大的表格:

列.key 列.value.string_value 列.value.int_value 列.value.float_value 列.value.boolean_value id
1 key1 aa null null null id1
key2 null null null false
key3 fa null null null
key4 null null null true
2 key1 ab null null null id1
key2 null null null false
key3 gf null null null
key4 null null null false
3 key1 af null null null id2
key2 null null null true
key3 fa null null null
key4 null null null false

我需要将其重新格式化如下:

key1 key2 key3 key4 id
1 aa false fa true id1
2 ab false gf false id1
3 af true fa false id2

我尝试使用以下链接中的方法,但无法在我的表格中使其工作:

https://stackoverflow.com/questions/63989161/how-to-unnest-and-pivot-two-columns-in-bigquery

我的表格中一个重要的问题是,就像上面的表格一样,id在不同行重复出现,但对于相同的键具有不同的值。在id重复的情况下,我仍然希望保留所有id的出现次数,就像在格式化的表格示例中一样。

此外,我在这里只列出了4个键,但实际上有50个,所以尽量减少手动操作是更好的。如果唯一的方法是手动编写每个列,那我仍然会这样做。

有人知道如何做吗?我基本上需要将每个键转换为新的列,并将其与id关联的相应值,但我不知道如何做。

非常感谢!

英文:

I have a very big table in BigQuery formatted as follows:

row column.key column.value.string_value column.value.int_value column.value.float_value column.value.boolean_value id
1 key1 aa null null null id1
key2 null null null false
key3 fa null null null
key4 null null null true
2 key1 ab null null null id1
key2 null null null false
key3 gf null null null
key4 null null null false
3 key1 af null null null id2
key2 null null null true
key3 fa null null null
key4 null null null false

I need to re-format it as follows:

row key1 key2 key3 key4 id
1 aa false fa true id1
2 ab false gf false id1
3 af true fa false id2

I tried to use this but couldn't make it work in my table

https://stackoverflow.com/questions/63989161/how-to-unnest-and-pivot-two-columns-in-bigquery

One important thing in my table is that, like in the above table, the ids repeat in different rows but have different values for the same keys. Where the ids repeat I want to still have all incidences of the ids, like in the formatted table example.

Also I put only 4 keys here but I actually have 50, so the least manual it is, the better. If the only way is writing each column manually then I'll still do it though.

Does anyone know how to do it? I basically need to turn every key into a new column with it's corresponding value associated with the ids, but I don't know how to do it.

Thank you very much!

答案1

得分: 1

要重新格式化它,首先需要将 column.value 中的 struct 合并为一个单一的列值。这可以通过使用 COALESCE 函数轻松完成,因为在 Google Analytics 的 column.value 结构中通常只有一个 非空 值。

COALESCE(
  value.string_value, 
  '' || value.int_value, -- 将 int64 转换为字符串
  '' || value.float_value,
  '' || value.boolean_value
) value,

之后,您可以使用 PIVOT 查询来简单地重塑它。

SELECT * FROM (
  SELECT t.* EXCEPT(column),
         key,
         COALESCE(
           value.string_value, 
           '' || value.int_value,
           '' || value.float_value,
           '' || value.boolean_value
         ) value,
    FROM sample_table t, UNNEST(column)
) PIVOT (ANY_VALUE(value) FOR key IN ('key1', 'key2', 'key3', 'key4'));

查询结果

Bigquery unnest 和 pivot 列

sample_table

WITH sample_table AS (
SELECT 1 row,
       'id1' id,
       [STRUCT('key1' AS key, STRUCT('aa' AS string_value, INT64(null) AS int_value, FLOAT64(null) AS float_value, BOOL(null) AS boolean_value) AS value),
        STRUCT('key2' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value),
        STRUCT('key3' AS key, STRUCT('fa' AS string_value, null AS int_value, null AS float_value, null AS boolean_value) AS value),
        STRUCT('key4' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, true AS boolean_value) AS value)] column
 UNION ALL
SELECT 2 row, 'id1' id,
       [STRUCT('key1' AS key, STRUCT('ab' AS string_value, INT64(null) AS int_value, FLOAT64(null) AS float_value, BOOL(null) AS boolean_value) AS value),
        STRUCT('key2' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value),
        STRUCT('key3' AS key, STRUCT('gf' AS string_value, null AS int_value, null AS float_value, null AS boolean_value) AS value),
        STRUCT('key4' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value)] column
 UNION ALL
SELECT 3 row, 'id2' id,
       [STRUCT('key1' AS key, STRUCT('af' AS string_value, INT64(null) AS int_value, FLOAT64(null) AS float_value, BOOL(null) AS boolean_value) AS value),
        STRUCT('key2' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, true AS boolean_value) AS value),
        STRUCT('key3' AS key, STRUCT('fa' AS string_value, null AS int_value, null AS float_value, null AS boolean_value) AS value),
        STRUCT('key4' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value)] column
)

如果您的表中有许多 ,您可以通过动态查询进一步概括它,参考您问题中的链接或以下链接:

英文:

In order to re-format it, firstly you need to merge column.value struct into one single column value. This can be easily done using COALESCE function since usually there is only one non-null value in column.value struct in Google Analytics.

COALESCE(
  value.string_value, 
  '' || value.int_value, -- to covert int64 to string
  '' || value.float_value,
  '' || value.boolean_value
) value,

After that, you can simply reshape it using PIVOT query.

SELECT * FROM (
  SELECT t.* EXCEPT(column),
         key,
         COALESCE(
           value.string_value, 
           '' || value.int_value,
           '' || value.float_value,
           '' || value.boolean_value
         ) value,
    FROM sample_table t, UNNEST(column)
) PIVOT (ANY_VALUE(value) FOR key IN ('key1', 'key2', 'key3', 'key4'));

Query results

Bigquery unnest 和 pivot 列

sample_table

WITH sample_table AS (
SELECT 1 row,
       'id1' id,
       [STRUCT('key1' AS key, STRUCT('aa' AS string_value, INT64(null) AS int_value, FLOAT64(null) AS float_value, BOOL(null) AS boolean_value) AS value),
        STRUCT('key2' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value),
        STRUCT('key3' AS key, STRUCT('fa' AS string_value, null AS int_value, null AS float_value, null AS boolean_value) AS value),
        STRUCT('key4' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, true AS boolean_value) AS value)] column
 UNION ALL
SELECT 2 row, 'id1' id,
       [STRUCT('key1' AS key, STRUCT('ab' AS string_value, INT64(null) AS int_value, FLOAT64(null) AS float_value, BOOL(null) AS boolean_value) AS value),
        STRUCT('key2' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value),
        STRUCT('key3' AS key, STRUCT('gf' AS string_value, null AS int_value, null AS float_value, null AS boolean_value) AS value),
        STRUCT('key4' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value)] column
 UNION ALL
SELECT 3 row, 'id2' id,
       [STRUCT('key1' AS key, STRUCT('af' AS string_value, INT64(null) AS int_value, FLOAT64(null) AS float_value, BOOL(null) AS boolean_value) AS value),
        STRUCT('key2' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, true AS boolean_value) AS value),
        STRUCT('key3' AS key, STRUCT('fa' AS string_value, null AS int_value, null AS float_value, null AS boolean_value) AS value),
        STRUCT('key4' AS key, STRUCT(null AS string_value, null AS int_value, null AS float_value, false AS boolean_value) AS value)] column
)

You can further generalize it with a dynamic query if you have many keys in your table refering to the link in your question or below.

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  • 本文由 发表于 2023年3月10日 01:56:25
  • 转载请务必保留本文链接:https://go.coder-hub.com/75688365.html
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