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Working With Json • Reviewed for ksqlDB 0.29
How to Read a JSON topic in ksqlDB
Use a PRINT statement to read a topic containing JSON records:
PRINT scores_topic FROM BEGINNING;
that returns :
Key format: ¯\_(Ä)_/¯ - no data processed
Value format: JSON or KAFKA_STRING
rowtime: 2022/07/19 10:18:13.763 Z, key: <null>, value: {"SCORE":4.9,"USER":{"NAME":"Charlie","AGE":54}}, partition: 4
rowtime: 2022/07/19 10:17:57.290 Z, key: <null>, value: {"SCORE":4.5,"USER":{"NAME":"Bob","AGE":25}}, partition: 0
rowtime: 2022/07/19 10:08:01.864 Z, key: <null>, value: {"SCORE":3.8,"USER":{"NAME":"Alice","AGE":30}}, partition: 3
If you need to run queries on the JSON topic, first you need to load the topic as a stream. Once you have the stream, you can query the JSON data in it.
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