[BEAM-7621] Selecting null row field's causes Null pointer Exception with BeamSql

• Type: Bug
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Affects Version/s: 2.14.0
• Fix Version/s: 2.16.0
• Component/s: dsl-sql
• Assignee: Unassigned
• Reporter: Vishwas
• Created: 24/Jun/19 06:40
• Updated: 16/May/20 13:42
• Resolved: 11/Jul/19 20:00

Description

I have below schema of the row:

  private static final Schema innerRowWithArraySchema =
      Schema.builder()
          .addStringField("string_field")
          .addArrayField("array_field", FieldType.INT64)
          .build();

private static final Schema nullableNestedRowWithArraySchema =
          Schema.builder()
              .addNullableField("field1",FieldType.row(innerRowWithArraySchema))
              .addNullableField("field2", FieldType.array(FieldType.row(innerRowWithArraySchema)))
              .build();

 

// Create a row with null values

Row nullRow = Row.nullRow(nullableNestedRowWithArraySchema);

 

Now when we try to select nested row field's NPE is thrown:

.apply(SqlTransform.query("select PCOLLECTION.field1.string_field as row_string_field, PCOLLECTION.field2[2].string_field as array_string_field from PCOLLECTION"));

 

Below is the exception thrown:

Caused by: java.lang.RuntimeException: CalcFn failed to evaluate:

{   final org.apache.beam.sdk.values.Row current = (org.apache.beam.sdk.values.Row) c.element();   *final java.util.List inp1_ = org.apache.beam.sdk.extensions.sql.impl.rel.BeamCalcRel.WrappedList.of(current.getRow(1));*   *final java.util.List inp2_ = org.apache.beam.sdk.extensions.sql.impl.rel.BeamCalcRel.WrappedList.of(current.getArray(2));*   c.output(org.apache.beam.sdk.values.Row.withSchema(outputSchema).addValue(inp1_ == null ? (String) null : (String) org.apache.beam.repackaged.beam_sdks_java_extensions_sql.org.apache.calcite.runtime.SqlFunctions.structAccess(inp1_, 0, "string_field")).addValue(org.apache.beam.repackaged.beam_sdks_java_extensions_sql.org.apache.calcite.runtime.SqlFunctions.arrayItemOptional(inp2_, 2) == null ? (String) null : (String) org.apache.beam.repackaged.beam_sdks_java_extensions_sql.org.apache.calcite.runtime.SqlFunctions.structAccess(org.apache.beam.repackaged.beam_sdks_java_extensions_sql.org.apache.calcite.runtime.SqlFunctions.arrayItemOptional(inp2_, 2), 0, "string_field")).build()); }

    at org.apache.beam.sdk.extensions.sql.impl.rel.BeamCalcRel$CalcFn.processElement(BeamCalcRel.java:253)
Caused by: java.lang.NullPointerException
    at org.apache.beam.sdk.extensions.sql.impl.rel.BeamCalcRel$WrappedList.of(BeamCalcRel.java:459)
    at SC.eval0(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

 

In BeamCalcRel.class field method, null values are not handled for composite types.

    public Expression field(BlockBuilder list, int index, Type storageType)

{      ....       }

else if (fromType.getTypeName().isCompositeType()
          || (fromType.getTypeName().isCollectionType()
              && fromType.getCollectionElementType().getTypeName().isCompositeType()))

{         field = Expressions.call(WrappedList.class, "of", field);  // List.of() is passed with null values       }

      ...
    }

 

 

Issue Links

• links to: GitHub Pull Request #8930
• links to: GitHub Pull Request #8930