BigQuery如何使用MERGE加载数组列

如何解决BigQuery如何使用MERGE加载数组列

我有一个要从GCS存储中加载的测试表：

CREATE OR REPLACE TABLE ta_producer_conformed.test
(
  id NUMERIC,array_string ARRAY<STRING>,array_struct_string_string ARRAY<STRUCT<key STRING,value STRING>>,array_struct_string_numeric ARRAY<STRUCT<key STRING,value NUMERIC>>,array_struct_string_int64 ARRAY<STRUCT<key STRING,value INT64>>
)

我已将外部存储表定义为：

{
  "autodetect": true,"csvOptions": {
    "encoding": "UTF-8","quote": "\"","fieldDelimiter": "\t"
  },"sourceFormat": "CSV","sourceUris": [
    "gs://my_bucket/test/input/*.tsv"
  ]
}

在其中，我使用JSON来保存数组类型：

"id"    "array_string"  "struct_string_string"  "struct_string_numberic"    "struct_string_int64"
1   ["one","two","three"] [{"key":"one","value":"1"},{"key":"two","value":"2"},{"key":"three","value":"3"}]    [{"key":"one","value":1.1},"value":2.2}] [{"key":"one","value":11},"value":22}]
2   ["four","five","six"] [{"key":"four","value":"4"},{"key":"five","value":"5"},{"key":"six","value":"6"}]    [{"key":"three","value":3.3},{"key":"four","value":4.4}]  [{"key":"three","value":33},"value":44}]

然后，我想使用MERGE在目标表中插入数据。当我运行此命令时：

CREATE TEMPORARY FUNCTION ARRAY_OF(json STRING)
RETURNS ARRAY<STRING>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
CREATE TEMPORARY FUNCTION ARRAY_STRUCT_STRING_STRING_OF(json STRING)
RETURNS ARRAY<STRUCT<key STRING,value STRING>>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
CREATE TEMPORARY FUNCTION ARRAY_STRUCT_STRING_NUMERIC_OF(json STRING)
RETURNS ARRAY<STRUCT<key STRING,value NUMERIC>>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
CREATE TEMPORARY FUNCTION ARRAY_STRUCT_STRING_INT64_OF(json STRING)
RETURNS ARRAY<STRUCT<key STRING,value INT64>>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
MERGE ta_producer_conformed.test T
USING ta_producer_raw.test_raw S
ON
    S.id = T.id
WHEN NOT MATCHED THEN
    INSERT (id,array_string,array_struct_string_string,array_struct_string_numeric,array_struct_string_int64)
    VALUES (
        id,ARRAY_OF(array_string),ARRAY_STRUCT_STRING_STRING_OF(struct_string_string),ARRAY_STRUCT_STRING_NUMERIC_OF(struct_string_numberic),ARRAY_STRUCT_STRING_INT64_OF(struct_string_int64)
    )
WHEN MATCHED THEN UPDATE SET
        T.id = S.id,T.array_string = ARRAY_OF(S.array_string),T.struct_string_string = ARRAY_STRUCT_STRING_STRING_OF(S.struct_string_string),T.ARRAY_STRUCT_STRING_NUMERIC_OF(S.struct_string_numberic),T.ARRAY_STRUCT_STRING_INT64_OF(S.struct_string_int64)

我收到此错误：

Error in query string: Error processing job 'xxxx-10843454-datamesh-
dev:bqjob_r4c426875_00000173fcfd2294_1': Syntax error: Expected "." or "=" or
"[" but got "(" at [1:1312]

如果我删除了“匹配时”的整个最后一部分，以使其仅插入，则临时功能可以正常工作。因此问题似乎在于，在THEN UPDATE SET的最后一节中，我无法使用临时功能。

如何理想地使用单个MERGE语句从外部存储桶中加载ARRAY<STRING>和ARRAY<STRUCT<STRING,STRING>>之类的数据类型？

更新：我尝试使用通用表表达式来预处理数据，方法是：

WITH cteConvertJason AS (
  SELECT 
        id,ARRAY_OF(array_string) AS array_string,ARRAY_STRUCT_STRING_STRING_OF(struct_string_string) AS struct_string_string,ARRAY_STRUCT_STRING_NUMERIC_OF(struct_string_numberic) AS struct_string_numberic,ARRAY_STRUCT_STRING_INT64_OF(struct_string_int64) AS struct_string_int64
  FROM
    ta_producer_raw.test_raw
)
MERGE ta_producer_conformed.test T
USING cteConvertJason S
...

这给出了一个错误，因此看起来您将WITH和MERGE组合在一起。

更新：出于遗留原因，我们正在尝试TSV。最好使用NEWLINE_DELIMITED_JSON作为格式，这样您就不必显式解析嵌套或重复的列。

解决方法

事实证明MERGE target USING source可以使用查询作为源。该查询可以运行临时功能来预处理源数据。然后，MERGE语句的其余部分可以正常工作：

CREATE TEMPORARY FUNCTION ARRAY_OF(json STRING)
RETURNS ARRAY<STRING>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
CREATE TEMPORARY FUNCTION ARRAY_STRUCT_STRING_STRING_OF(json STRING)
RETURNS ARRAY<STRUCT<key STRING,value STRING>>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
CREATE TEMPORARY FUNCTION ARRAY_STRUCT_STRING_NUMERIC_OF(json STRING)
RETURNS ARRAY<STRUCT<key STRING,value NUMERIC>>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
CREATE TEMPORARY FUNCTION ARRAY_STRUCT_STRING_INT64_OF(json STRING)
RETURNS ARRAY<STRUCT<key STRING,value INT64>>
LANGUAGE js AS """
  let parsed = JSON.parse(json);
  return parsed;
""";
MERGE ta_producer_conformed.test T
USING 
 (
  SELECT 
        id,ARRAY_OF(array_string) AS array_string,ARRAY_STRUCT_STRING_STRING_OF(struct_string_string) AS struct_string_string,ARRAY_STRUCT_STRING_NUMERIC_OF(struct_string_numberic) AS struct_string_numberic,ARRAY_STRUCT_STRING_INT64_OF(struct_string_int64) AS struct_string_int64
  FROM
    ta_producer_raw.test_raw
)
 S
ON
    S.id = T.id
WHEN NOT MATCHED THEN
    INSERT (id,array_string,array_struct_string_string,array_struct_string_numeric,array_struct_string_int64)
    VALUES (
        id,struct_string_string,struct_string_numberic,struct_string_int64
    )
WHEN MATCHED THEN UPDATE SET
        T.array_string = S.array_string,T.array_struct_string_string = S.struct_string_string,T.array_struct_string_numeric = S.struct_string_numberic,T.array_struct_string_int64 = S.struct_string_int64

BigQuery如何使用MERGE加载数组列

如何解决BigQuery如何使用MERGE加载数组列

解决方法

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