POSTGRESQL：错误：没有与 ON CONFLICT 规范匹配的唯一或排除约束

Question

我正在尝试使用以下查询对名为“message_payload”的表执行 upsert 操作，但出现错误：

错误：没有与 ON CONFLICT 规范 SQL 状态匹配的唯一或排除约束：42P10

询问：

    INSERT INTO public.error_message(
    id, created_by, created_dt, modified_by, modified_dt, attempt, message_headers, 
    message_main_topic, message_payload, message_status, message_status_code)
        VALUES (51, null, null, null, null, 1, '{
        "jsonContent": {
            "content-length": "1635",
            "message_status_code": "417",
            "cookie": "JSESSIONID=279AF4C174E6192BDAB11A067768BBD5",
            "postman-token": "f0f33e86-498f-452a-aaf6-18eb84dc5907",
            "kafka_timestampType": "CREATE_TIME",
            "message_id": "21",
            "kafka_receivedMessageKey": "null",
            "kafka_receivedTopic": "error-topic",
            "accept": "*/*",
            "kafka_offset": "33",
            "kafka_consumer": "org.apache.kafka.clients.consumer.KafkaConsumer@5091bb5f",
            "host": "localhost:8082",
            "content-type": "application/json",
            "connection": "keep-alive",
            "cache-control": "no-cache",
            "kafka_receivedPartitionId": "0",
            "kafka_receivedTimestamp": "1552305428711",
            "accept-encoding": "gzip, deflate",
            "message_main_topic": "ldarsQCustomStatistics.1",
            "user-agent": "PostmanRuntime/7.6.1"
        }
    }', 'ldarsQCustomStatistics.1', '{
        "jsonContent": {
            "messageTime": 16772223422,
            "messageRev": 9,
            "businessId": "DB",
            "messageId": "55"
        }
    }', 1, 201)
    ON CONFLICT ((message_payload->'jsonContent'->>'message_id'))
    DO UPDATE SET attempt = error_message.attempt + 1, message_headers = EXCLUDED.message_headers, 
                  message_status_code = EXCLUDED.message_status_code, message_status = EXCLUDED.message_status, 
                  created_by = EXCLUDED.created_by, created_dt = EXCLUDED.created_dt, 
                  modified_by = EXCLUDED.modified_by, modified_dt = EXCLUDED.modified_dt, 
                  message_main_topic = EXCLUDED.message_main_topic, message_payload = EXCLUDED.message_payload, 
                  id = DEFAULT

Answer 1

您很可能缺少此特定字段的唯一约束。

例子：

CREATE UNIQUE INDEX j_msgid_idx ON public.error_message((data->'jsonContent'->>'message_id'));