[
https://issues.apache.org/jira/browse/FLINK-34656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17830816#comment-17830816
]
yisha zhou commented on FLINK-34656:
------------------------------------
[~libenchao] Hi ,sorry for the late reply. To reproduce the problem, you can
add code below in
`org.apache.flink.table.planner.runtime.stream.sql.CalcITCase`:
{code:java}
@Test
def testElementGet(): Unit = {
val sqlQuery =
s"""
| SELECT a[1] FROM MyTableRow
|""".stripMargin
val rowData1: GenericRowData = new GenericRowData(2)
rowData1.setField(0, null)
val data = List(rowData1)
implicit val dataType: TypeInformation[GenericRowData] =
InternalTypeInfo
.ofFields(ARRAY(BIGINT.notNull()).nullable().getLogicalType)
.asInstanceOf[TypeInformation[GenericRowData]]
val ds = env.fromCollection(data)
val t = ds.toTable(tEnv, 'a)
tEnv.createTemporaryView("MyTableRow", t)
val outputType = InternalTypeInfo.ofFields(new BigIntType())
val result = tEnv.sqlQuery(sqlQuery)
val sink = new TestingAppendRowDataSink(outputType)
tEnv.toDataStream(result, outputType.getDataType).addSink(sink)
env.execute()
val expected = List(
"+I(-1)"
)
assertThat(sink.getAppendResults.sorted).isEqualTo(expected.sorted)
} {code}
The root reason is that element is of not-null type, therefore the nullTerm
won't be checked.
> Generated code for `ITEM` operator should return null when getting element of
> a null map/array/row
> --------------------------------------------------------------------------------------------------
>
> Key: FLINK-34656
> URL: https://issues.apache.org/jira/browse/FLINK-34656
> Project: Flink
> Issue Type: Bug
> Components: Table SQL / Planner
> Affects Versions: 1.20.0
> Reporter: yisha zhou
> Priority: Major
>
> In FieldAccessFromTableITCase we can find that the expected result of f0[1]
> is null when f0 is a null array.
> However, behavior in generated code for ITEM is not consistent with case
> above. The main code is:
>
> {code:java}
> val arrayAccessCode =
> s"""
> |${array.code}
> |${index.code}
> |boolean $nullTerm = ${array.nullTerm} || ${index.nullTerm} ||
> | $idxStr < 0 || $idxStr >= ${array.resultTerm}.size() || $arrayIsNull;
> |$resultTypeTerm $resultTerm = $nullTerm ? $defaultTerm : $arrayGet;
> |""".stripMargin {code}
> If `array.nullTerm` is true, a default value of element type will be
> returned, for example -1 for null bigint array.
> The reason why FieldAccessFromTableITCase can get expected result is that the
> ReduceExpressionsRule generated an expression code for that case like:
> {code:java}
> boolean isNull$0 = true || false ||
> ((int) 1) - 1 < 0 || ((int) 1) - 1 >=
> ((org.apache.flink.table.data.ArrayData) null).size() ||
> ((org.apache.flink.table.data.ArrayData) null).isNullAt(((int) 1) - 1);
> long result$0 = isNull$0 ? -1L : ((org.apache.flink.table.data.ArrayData)
> null).getLong(((int) 1) - 1);
> if (isNull$0) {
> out.setField(0, null);
> } else {
> out.setField(0, result$0);
> } {code}
> The reduced expr will be a null literal.
>
> I think the behaviors for getting element of a null value should be unified.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
