CREATE OR REPLACE STREAM "DESTINATION_SQL_STREAM" (col1 INTEGER, col2 VARCHAR(16), JSON_DATA VARCHAR(MAX));
CREATE OR REPLACE PUMP "STREAM_PUMP" AS INSERT INTO "DESTINATION_SQL_STREAM" SELECT col1, col2, TO_BASE64(TO_JSON(get_json_object(JSON_DATA, '$'))) FROM "SOURCE_SQL_STREAM_001";
pip install apache-flink
pip install jsonpath_ng
4.然后,需要对代码中的嵌套JSON数据进行扁平化处理。这可以通过以下步骤实现:
a) 将嵌套的JSON数据转换为Python对象:
import json
from pyflink.common.serialization import SimpleStringSchema
from pyflink.datastream import StreamExecutionEnvironment
from pyflink.datastream.connectors import FlinkKinesisProducer
from jsonpath_ng import parse
env = StreamExecutionEnvironment.get_execution_environment()
source_stream = env.add_source(flink_consumer)
data_stream = source_stream.map(lambda x: json.loads(x))
b) 通过jsonpath_ng库筛选原始JSON数据并创建新列:
parser = parse('$.prop1')
data_stream = data_stream.map(lambda x: (x, [match.value for match in parser.find(x)]))
c) 将嵌套对象中的所有键/值对移动到单个JSON对象中:
def flatten(data):
for key, value in data.items():
if isinstance(value, dict):
for inner_key, inner_value in flatten(value).items():
yield key + "." + inner_key, inner_value
elif isinstance(value, list):
for remaining in value