[
https://issues.apache.org/jira/browse/FLINK-13503?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jing Zhang updated FLINK-13503:
-------------------------------
Description:
I think we should add contract in `LookupableTableSource` to specify expected
behavior when the lookupKeys contains null value. Because there is ambiguity
here, for example, one input record of eval method is (null,1):
* to ignore null value, that is, in the above example, only looks `b = 1`
* to lookup `is value`, that is, in the above example, only looks `a is null
and b = 1`
* to return empty records, that is, in the above example, only looks `a =
null and b = 1`
In fact, there are different behavior in current code.
For example, in Jdbc connector,
The query template in `JdbcLookUpFunction` like:
SELECT c, d, e, f from T where a = ? and b = ?
If pass (null, 1) to `eval` method, it will generate the following query:
SELECT c, d, e, f from T where a = null and b = 1
Which always outputs empty records.
BTW, Is this behavior reasonable?
and the `InMemoryLookupableTableSource` behaviors like point 2 in the above
list.
was:
I think we should add contract in `LookupableTableSource` to specify expected
behavior when the lookupKeys contains null value. Because there is ambiguity
here:
* to ignore null value, that is, in the above example, only looks `b = 1`
* to lookup `is value`, that is, in the above example, only looks `a is null
and b = 1`
* to return empty records, that is, in the above example, only looks `a =
null and b = 1`
In fact, there are different behavior in current code.
For example, in Jdbc connector,
The query template in `JdbcLookUpFunction` like:
SELECT c, d, e, f from T where a = ? and b = ?
If pass (null, 1) to `eval` method, it will generate the following query:
SELECT c, d, e, f from T where a = null and b = 1
Which always outputs empty records.
BTW, Is this behavior reasonable?
and the `InMemoryLookupableTableSource` behaviors like point 2 in the above
list.
> Add contract in `LookupableTableSource` to specify the behavior when
> lookupKeys contains null
> ---------------------------------------------------------------------------------------------
>
> Key: FLINK-13503
> URL: https://issues.apache.org/jira/browse/FLINK-13503
> Project: Flink
> Issue Type: Task
> Components: Connectors / JDBC
> Affects Versions: 1.9.0, 1.10
> Reporter: Jing Zhang
> Priority: Minor
>
> I think we should add contract in `LookupableTableSource` to specify expected
> behavior when the lookupKeys contains null value. Because there is ambiguity
> here, for example, one input record of eval method is (null,1):
> * to ignore null value, that is, in the above example, only looks `b = 1`
> * to lookup `is value`, that is, in the above example, only looks `a is
> null and b = 1`
> * to return empty records, that is, in the above example, only looks `a =
> null and b = 1`
> In fact, there are different behavior in current code.
> For example, in Jdbc connector,
> The query template in `JdbcLookUpFunction` like:
> SELECT c, d, e, f from T where a = ? and b = ?
> If pass (null, 1) to `eval` method, it will generate the following query:
> SELECT c, d, e, f from T where a = null and b = 1
> Which always outputs empty records.
> BTW, Is this behavior reasonable?
> and the `InMemoryLookupableTableSource` behaviors like point 2 in the above
> list.
--
This message was sent by Atlassian JIRA
(v7.6.14#76016)
