after we change the String[] fields to Integer[] fields , the problem still occurs.
------------ our runnable test is at https://github.com/guxiaobo/calcite-json-adapter/blob/main/src/test/java/org/apache/calcite/adapter/json/test/JsonSchemaTest.java ------- @Test public void test1_2()throws SQLException{ Map<string, list<jsonobject="">> map = makeJsonMap(); Schema schema = new JsonSchema<>("js", map); CalciteConnection conn = this.openConn1(schema, "js"); System.out.println("c1 + c11 = " + exeGetLong(conn, "select c1 + c11 from js.t1")); conn.close(); } ------- java.sql.SQLException: Error while executing SQL "select c1 + c11 from js.t1": Error while applying rule JsonProjectTableScanRule, args [rel#11:LogicalProject.NONE.[](input=RelSubset#10,exprs=[+($9, $3)]), rel#1:JsonTableScan.ENUMERABLE.[](table=[js, t1])] at org.apache.calcite.avatica.Helper.createException(Helper.java:56) at org.apache.calcite.avatica.Helper.createException(Helper.java:41) at org.apache.calcite.avatica.AvaticaStatement.executeInternal(AvaticaStatement.java:163) at org.apache.calcite.avatica.AvaticaStatement.executeQuery(AvaticaStatement.java:227) at org.apache.calcite.adapter.json.test.BaseTest.exeGetLong(BaseTest.java:37) at org.apache.calcite.adapter.json.test.JsonSchemaTest.test1_2(JsonSchemaTest.java:76) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63) at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329) at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.ParentRunner.run(ParentRunner.java:413) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:93) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:40) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:529) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:756) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:452) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:210) Caused by: java.lang.RuntimeException: Error while applying rule JsonProjectTableScanRule, args [rel#11:LogicalProject.NONE.[](input=RelSubset#10,exprs=[+($9, $3)]), rel#1:JsonTableScan.ENUMERABLE.[](table=[js, t1])] at org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:250) at org.apache.calcite.plan.volcano.IterativeRuleDriver.drive(IterativeRuleDriver.java:59) at org.apache.calcite.plan.volcano.VolcanoPlanner.findBestExp(VolcanoPlanner.java:523) at org.apache.calcite.tools.Programs.lambda$standard$3(Programs.java:276) at org.apache.calcite.tools.Programs$SequenceProgram.run(Programs.java:336) at org.apache.calcite.prepare.Prepare.optimize(Prepare.java:177) at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:312) at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:220) at org.apache.calcite.prepare.CalcitePrepareImpl.prepare2_(CalcitePrepareImpl.java:647) at org.apache.calcite.prepare.CalcitePrepareImpl.prepare_(CalcitePrepareImpl.java:513) at org.apache.calcite.prepare.CalcitePrepareImpl.prepareSql(CalcitePrepareImpl.java:483) at org.apache.calcite.jdbc.CalciteConnectionImpl.parseQuery(CalciteConnectionImpl.java:249) at org.apache.calcite.jdbc.CalciteMetaImpl.prepareAndExecute(CalciteMetaImpl.java:623) at org.apache.calcite.avatica.AvaticaConnection.prepareAndExecuteInternal(AvaticaConnection.java:674) at org.apache.calcite.avatica.AvaticaStatement.executeInternal(AvaticaStatement.java:156) ... 29 more Caused by: java.lang.RuntimeException: Error occurred while applying rule JsonProjectTableScanRule at org.apache.calcite.plan.volcano.VolcanoRuleCall.transformTo(VolcanoRuleCall.java:157) at org.apache.calcite.plan.RelOptRuleCall.transformTo(RelOptRuleCall.java:269) at org.apache.calcite.plan.RelOptRuleCall.transformTo(RelOptRuleCall.java:284) at org.apache.calcite.adapter.json.JsonProjectTableScanRule.onMatch(JsonProjectTableScanRule.java:30) at org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:223) ... 43 more Caused by: java.lang.NullPointerException at org.apache.calcite.adapter.json.JsonTableScan.lambda$0(JsonTableScan.java:45) at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948) at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658) at org.apache.calcite.adapter.json.JsonTableScan.deriveRowType(JsonTableScan.java:45) at org.apache.calcite.rel.AbstractRelNode.getRowType(AbstractRelNode.java:173) at org.apache.calcite.plan.volcano.VolcanoPlanner.register(VolcanoPlanner.java:587) at org.apache.calcite.plan.volcano.VolcanoPlanner.ensureRegistered(VolcanoPlanner.java:613) at org.apache.calcite.plan.volcano.VolcanoRuleCall.transformTo(VolcanoRuleCall.java:144) ... 47 more</string,>
