[FLINK-20725] TableFunction#getTypeInference is not work well for JdbcRowDataLookupFunction, it's always throws Exception

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 1.13.0
• Component/s: Table SQL / API
• Assignee: Unassigned
• Reporter: Lijie Wang
• Created: 22/Dec/20 16:01
• Updated: 12/Jan/21 09:22
• Resolved: 12/Jan/21 09:22

Description

I found that TableFunction#getTypeInference  is not work well for JdbcRowDataLookupFunction , it's always throws Exception.

 

When I add following test in JdbcRowDataLookupFunctionTest and run it:

@Test
public void testTypeInference() {
   final TableEnvironment env = TableEnvironment.create(EnvironmentSettings
      .newInstance().build());

   final DataTypeFactory dataTypeFactory = ((TableEnvironmentInternal) env)
      .getCatalogManager()
      .getDataTypeFactory();

   JdbcRowDataLookupFunction lookupFunction = buildRowDataLookupFunction();

   lookupFunction.getTypeInference(dataTypeFactory);
}

 

it always throws following exception:

 

Test testTypeInference(org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunctionTest) failed with:
org.apache.flink.table.api.ValidationException: Could not extract a valid type inference for function class 'org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction'. Please check for implementation mistakes and/or provide a corresponding hint. 
    at org.apache.flink.table.types.extraction.ExtractionUtils.extractionError(ExtractionUtils.java:359) 
    at org.apache.flink.table.types.extraction.TypeInferenceExtractor.extractTypeInference(TypeInferenceExtractor.java:160) 
    at org.apache.flink.table.types.extraction.TypeInferenceExtractor.forTableFunction(TypeInferenceExtractor.java:119) 
    at org.apache.flink.table.functions.TableFunction.getTypeInference(TableFunction.java:212) 
    at org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunctionTest.testTypeInference(JdbcRowDataLookupFunctionTest.java:103)
Caused by: org.apache.flink.table.api.ValidationException: Error in extracting a signature to output mapping. 
    at org.apache.flink.table.types.extraction.ExtractionUtils.extractionError(ExtractionUtils.java:359) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.extractOutputMapping(FunctionMappingExtractor.java:118) 
    at org.apache.flink.table.types.extraction.TypeInferenceExtractor.extractTypeInferenceOrError(TypeInferenceExtractor.java:170) 
    at org.apache.flink.table.types.extraction.TypeInferenceExtractor.extractTypeInference(TypeInferenceExtractor.java:158) 
    ... 32 more
Caused by: org.apache.flink.table.api.ValidationException: Unable to extract a type inference from method:
public void org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction.eval(java.lang.Object[]) 
    at org.apache.flink.table.types.extraction.ExtractionUtils.extractionError(ExtractionUtils.java:359) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.extractResultMappings(FunctionMappingExtractor.java:175) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.extractOutputMapping(FunctionMappingExtractor.java:113) 
    ... 34 more
Caused by: org.apache.flink.table.api.ValidationException: Could not extract a data type from 'interface org.apache.flink.table.data.RowData' in generic class 'org.apache.flink.table.functions.TableFunction' in class org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction. Please pass the required data type manually or allow RAW types. 
    at org.apache.flink.table.types.extraction.ExtractionUtils.extractionError(ExtractionUtils.java:359) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.extractDataTypeOrRawWithTemplate(DataTypeExtractor.java:273) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.extractDataTypeOrRaw(DataTypeExtractor.java:249) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.extractDataTypeWithClassContext(DataTypeExtractor.java:223) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.extractFromGeneric(DataTypeExtractor.java:144) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.lambda$createGenericResultExtraction$13(FunctionMappingExtractor.java:467) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.putExtractedResultMappings(FunctionMappingExtractor.java:312) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.collectMethodMappings(FunctionMappingExtractor.java:255) 
    at org.apache.flink.table.types.extraction.FunctionMappingExtractor.extractResultMappings(FunctionMappingExtractor.java:167) 
    ... 35 more
Caused by: org.apache.flink.table.api.ValidationException: Cannot extract a data type from an internal 'org.apache.flink.table.data.RowData' class without further information. Please use annotations to define the full logical type. 
    at org.apache.flink.table.types.extraction.ExtractionUtils.extractionError(ExtractionUtils.java:359) 
    at org.apache.flink.table.types.extraction.ExtractionUtils.extractionError(ExtractionUtils.java:351) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.checkForCommonErrors(DataTypeExtractor.java:401) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.extractDataTypeOrError(DataTypeExtractor.java:304) 
    at org.apache.flink.table.types.extraction.DataTypeExtractor.extractDataTypeOrRawWithTemplate(DataTypeExtractor.java:265) 
    ... 42 more

 

I guess this problem also exists in other LookupFunction implementations. And the reason why there was no problem when running itcase(JdbcLookupTableITCase) is that the exception was caught and handled in LookupJoinCodeGenerator#createLookupTypeInference.

 

Issue Links

• relates to: FLINK-18890 Update LookupTableSource to the new type system