28. PyFlink入门--Table API 处理json数据操作案例

python --version

python -m pip install apache-flink==1.16.0

python -m pip install apache-flink==1.16.0 -i https://pypi.tuna.tsinghua.edu.cn/simple

import json
import logging
import sys


from pyflink.table import (EnvironmentSettings, TableEnvironment, DataTypes, TableDescriptor,
                           Schema)
from pyflink.table.expressions import col
from pyflink.table.udf import udf




def process_json_data_with_udf():
    t_env = TableEnvironment.create(EnvironmentSettings.in_streaming_mode())


    # define the source
    table = t_env.from_elements(
        elements=[
            (1, '{"name": "Flink", "tel": 123, "addr": {"country": "Germany", "city": "Berlin"}}'),
            (2, '{"name": "hello", "tel": 135, "addr": {"country": "China", "city": "Shanghai"}}'),
            (3, '{"name": "world", "tel": 124, "addr": {"country": "USA", "city": "NewYork"}}'),
            (4, '{"name": "PyFlink", "tel": 32, "addr": {"country": "China", "city": "Hangzhou"}}')
        ],
        schema=['id', 'data'])


    # define the sink
    t_env.create_temporary_table(
        'sink',
        TableDescriptor.for_connector('print')
        .schema(Schema.new_builder()
                .column('id', DataTypes.BIGINT())
                .column('data', DataTypes.STRING())
                .build())
        .build())


    # update json columns
    @udf(result_type=DataTypes.STRING())
    def update_tel(data):
        json_data = json.loads(data)
        json_data['tel'] += 1
        return json.dumps(json_data)


    table = table.select(col('id'), update_tel(col('data')))


    # execute
    table.execute_insert('sink') \
        .wait()
    # remove .wait if submitting to a remote cluster, refer to
    # https://nightlies.apache.org/flink/flink-docs-stable/docs/dev/python/faq/#wait-for-jobs-to-finish-when-executing-jobs-in-mini-cluster
    # for more details




if __name__ == '__main__':
    logging.basicConfig(stream=sys.stdout, level=logging.INFO, format="%(message)s")


    process_json_data_with_udf()

python process_json_data_with_udf.py

8> +I[1, {"name": "Flink", "tel": 124, "addr": {"country": "Germany", "city": "Berlin"}}]
8> +I[2, {"name": "hello", "tel": 136, "addr": {"country": "China", "city": "Shanghai"}}]
8> +I[3, {"name": "world", "tel": 125, "addr": {"country": "USA", "city": "NewYork"}}]
8> +I[4, {"name": "PyFlink", "tel": 33, "addr": {"country": "China", "city": "Hangzhou"}}]