时态表函数:无法将不同类型的表达式添加到集合中

Question

我正在使用时态表函数来连接这样的两个流，但出现了这个错误。集合类型和表达式类型之间的差异是proctime0的类型，它具有NOT NULL

不同会如何出现，以及有什么方法可以解决这个问题？

Exception in thread "main" java.lang.AssertionError: Cannot add expression of different type to set:
set type is RecordType(VARCHAR(2147483647) CHARACTER SET "UTF-16LE" order_id, DECIMAL(32, 2) price, VARCHAR(2147483647) CHARACTER SET "UTF-16LE" currency, TIMESTAMP(3) order_time, TIMESTAMP_LTZ(3) *PROCTIME* NOT NULL proctime, VARCHAR(2147483647) CHARACTER SET "UTF-16LE" currency0, BIGINT conversion_rate, TIMESTAMP(3) update_time, TIMESTAMP_LTZ(3) *PROCTIME* proctime0) NOT NULL
expression type is RecordType(VARCHAR(2147483647) CHARACTER SET "UTF-16LE" order_id, DECIMAL(32, 2) price, VARCHAR(2147483647) CHARACTER SET "UTF-16LE" currency, TIMESTAMP(3) order_time, TIMESTAMP_LTZ(3) *PROCTIME* NOT NULL proctime, VARCHAR(2147483647) CHARACTER SET "UTF-16LE" currency0, BIGINT conversion_rate, TIMESTAMP(3) update_time, TIMESTAMP_LTZ(3) *PROCTIME* NOT NULL proctime0) NOT NULL
set is rel#61:LogicalCorrelate.NONE.any.None: 0.[NONE].[NONE](left=HepRelVertex#59,right=HepRelVertex#60,correlation=$cor0,joinType=inner,requiredColumns={4})
expression is LogicalJoin(condition=[__TEMPORAL_JOIN_CONDITION($4, $7, __TEMPORAL_JOIN_CONDITION_PRIMARY_KEY($5))], joinType=[inner])
LogicalProject(order_id=[$0], price=[$1], currency=[$2], order_time=[$3], proctime=[PROCTIME()])
LogicalTableScan(table=[[default_catalog, default_database, orders]])
LogicalProject(currency=[$0], conversion_rate=[$1], update_time=[$2], proctime=[PROCTIME()])
LogicalTableScan(table=[[default_catalog, default_database, currency_rates]])

事实表：

CREATE TABLE `orders` (
order_id    STRING,
price       DECIMAL(32,2),
currency    STRING,
order_time  TIMESTAMP(3),
proctime as PROCTIME()
) WITH (
'properties.bootstrap.servers' = '127.0.0.1:9092',
'properties.group.id' = 'test',
'scan.topic-partition-discovery.interval' = '10000',
'connector' = 'kafka',
'format' = 'json',
'scan.startup.mode' = 'latest-offset', 
'topic' = 'test1'
) 

构建表：

CREATE TABLE `currency_rates` (
currency    STRING,
conversion_rate BIGINT,
update_time  TIMESTAMP(3),
proctime as PROCTIME()
) WITH (
'properties.bootstrap.servers' = '127.0.0.1:9092',
'properties.group.id' = 'test',
'scan.topic-partition-discovery.interval' = '10000',
'connector' = 'kafka',
'format' = 'json',
'scan.startup.mode' = 'latest-offset', 
'topic' = 'test3'
) 

生成表格函数的方法：

TemporalTableFunction table_rate = tEnv.from("currency_rates")
.createTemporalTableFunction("update_time", "currency");
tEnv.registerFunction("rates", table_rate); 

加入逻辑：

SELECT
order_id,
price,
s.currency,
conversion_rate,
order_time
FROM orders AS o,  
LATERAL TABLE (rates(o.proctime)) AS s
WHERE o.currency = s.currency 

Answer 1

尝试使用tEnv.createTemporarySystemFunction("rates"，table_rate(，而不是使用.registerFunction((