[FLINK-24997] count(null) not supported in flink sql query

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.14.0
• Component/s: Table SQL / Client, Table SQL / Planner
• Assignee: Unassigned
• Reporter: KevinyhZou
• Created: 22/Nov/21 13:42
• Updated: 23/Nov/21 04:30

Description

I use sql client to submit a sql query to flink session cluster,  the sql is 

select count(null);

  it submit failed and throws the exception

org.apache.flink.table.client.gateway.SqlExecutionException: Could not execute SQL statement.
        at org.apache.flink.table.client.gateway.local.LocalExecutor.executeOperation(LocalExecutor.java:211) ~[flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.gateway.local.LocalExecutor.executeQuery(LocalExecutor.java:231) ~[flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.cli.CliClient.callSelect(CliClient.java:532) ~[flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.cli.CliClient.callOperation(CliClient.java:423) ~[flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.cli.CliClient.lambda$executeStatement$1(CliClient.java:332) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at java.util.Optional.ifPresent(Optional.java:183) ~[?:?]
        at org.apache.flink.table.client.cli.CliClient.executeStatement(CliClient.java:325) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.cli.CliClient.executeInteractive(CliClient.java:297) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.cli.CliClient.executeInInteractiveMode(CliClient.java:221) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.SqlClient.openCli(SqlClient.java:151) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.SqlClient.start(SqlClient.java:95) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.SqlClient.startClient(SqlClient.java:187) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.client.SqlClient.main(SqlClient.java:161) [flink-sql-client_2.12-1.14.0.jar:1.14.0]
Caused by: java.lang.UnsupportedOperationException: Unsupported type 'NULL' to get internal serializer
        at org.apache.flink.table.runtime.typeutils.InternalSerializers.createInternal(InternalSerializers.java:125) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.runtime.typeutils.InternalSerializers.create(InternalSerializers.java:55) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195) ~[?:?]
        at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948) ~[?:?]
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:550) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260) ~[?:?]
        at java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:517) ~[?:?]
        at org.apache.flink.table.runtime.typeutils.RowDataSerializer.<init>(RowDataSerializer.java:73) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.runtime.typeutils.InternalSerializers.createInternal(InternalSerializers.java:109) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.runtime.typeutils.InternalSerializers.create(InternalSerializers.java:55) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.runtime.typeutils.InternalTypeInfo.of(InternalTypeInfo.java:83) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.planner.plan.nodes.exec.common.CommonExecCalc.translateToPlanInternal(CommonExecCalc.java:106) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.planner.plan.nodes.exec.ExecNodeBase.translateToPlan(ExecNodeBase.java:134) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.planner.plan.nodes.exec.ExecEdge.translateToPlan(ExecEdge.java:250) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.planner.plan.nodes.exec.stream.StreamExecExchange.translateToPlanInternal(StreamExecExchange.java:75) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.planner.plan.nodes.exec.ExecNodeBase.translateToPlan(ExecNodeBase.java:134) ~[flink-table_2.12-1.14.0.jar:1.14.0]
        at org.apache.flink.table.planner.plan.nodes.exec.ExecEdge.translateToPlan(ExecEdge.java:250) ~[flink-table_2.12-1.14.0.jar:1.14.0]