ksqlDB：使用嵌套结构连接 tables/streams（未展平）

Question

我得到了两个不同的主题，它们各自采用 avro 格式的架构，X 和 Y。这两个主题都有很多字段。我想在它们之间创建一个 table-stream 连接关系，并按以下格式将其输出到另一个主题：

{
   id, // the id used to join them
   x_name : X,
   y_name: Y
}

换句话说，我想加入这两个嵌套的每个源。我能够以正常方式加入他们，但是所有领域都被夷为平地。这可以用 KsqlDB 实现吗？我试图找到一个没有成功的好方法。

编辑：

添加更多信息和示例。假设我有两个具有此类数据的主题。

product_supply

{
  "product_id": 1,
  "name": "name",
  "stock": 11
  "price": "141",
  "storage_ids": [1, 2, 3]
}

product_information

{
  "product_id": 1,
  "description": "151",
  "manufacturer": "ABC"
  "Vendor_id": "5"
}

我想使用 KsqlDB 以非扁平化方式连接这些 table 并发布到一个主题，如下所示：

{
  "product_id": 1,
  "product_information": {
      "product_id": 1,
      "description": "151",
      "manufacturer": "ABC"
      "Vendor_id": "5"
  }
  "product_supply": {
      "product_id": 1,
      "name": "name",
      "stock": 11
      "price": "141",
      "storage_ids": [1, 2, 3]
  }
}

我已经为每个主题添加了架构，如果可能的话，我希望使用这些架构而不必在 ksql 中显式定义每个字段。

Answer 1

working with structured data in ksqlDB 上有一个很好的指南。基于此，我能够让它工作：

创建示例数据

CREATE STREAM PRODUCT_SUPPLY (PRODUCT_ID INT, NAME VARCHAR, STOCK INT, PRICE INT, STORAGE_IDS ARRAY<INT>) WITH (KAFKA_TOPIC='PRODUCT_SUPPLY', REPLICAS=1,PARTITIONS=6,VALUE_FORMAT='AVRO');
CREATE TABLE PRODUCT_INFORMATION (PRODUCT_ID INT PRIMARY KEY, DESCRIPTION VARCHAR, MANUFACTURER VARCHAR, VENDOR_ID INT) WITH (KAFKA_TOPIC='PRODUCT_INFO', REPLICAS=1,PARTITIONS=6,VALUE_FORMAT='AVRO');
INSERT INTO PRODUCT_SUPPLY VALUES(1,'NAME',11,141,ARRAY[1,2,3]);
INSERT INTO PRODUCT_INFORMATION values (1,'151','abc',5);

查询数据

SET 'auto.offset.reset' = 'earliest';

SELECT PS.PRODUCT_ID AS PRODUCT_ID,
      STRUCT(NAME        := PS.NAME,
              STOCK       := PS.STOCK,
              PRICE       := PS.PRICE,
              STORAGE_IDS := PS.STORAGE_IDS) AS PRODUCT_SUPPLY,
      STRUCT(DESCRIPTION  := PI.DESCRIPTION,
              MANUFACTURER := PI.MANUFACTURER,
              VENDOR_ID    := PI.VENDOR_ID) AS PRODUCT_INFORMATION
  FROM PRODUCT_SUPPLY PS
      LEFT JOIN PRODUCT_INFORMATION PI
      ON PS.PRODUCT_ID=PI.PRODUCT_ID
EMIT CHANGES LIMIT 1;

+-------------------------+-------------------------+-------------------------+
|PRODUCT_ID               |PRODUCT_SUPPLY           |PRODUCT_INFORMATION      |
+-------------------------+-------------------------+-------------------------+
|1                        |{NAME=NAME, STOCK=11, PRI|{DESCRIPTION=151, MANUFAC|
|                         |CE=141, STORAGE_IDS=[1, 2|TURER=abc, VENDOR_ID=5}  |
|                         |, 3]}                    |                         |
Limit Reached
Query terminated

ksqlDB：使用嵌套结构连接 tables/streams（未展平）

ksqlDB: Joining tables/streams with nested structure(not flattened)

apache-kafka

confluent-platform

ksqldb