title: How to use Apache Beam DSL APIs?
body: <p>I am trying to implement the DSL API example from the <a href="https://beam.apache.org/documentation/dsls/sql" rel="nofollow noreferrer">Apache Beam documentation</a>. I am using the newest versions of the apache beam libraries (2.4.0)</p>
  
  <p>The code I am running is the same as in the docs:</p>
  
  <pre><code>@Rule
  public final transient TestPipeline p = TestPipeline.create();
  
  @Test
  public void dslTest() {
      RowType appType = RowSqlType
              .builder()
              .withIntegerField("appId")
              .withVarcharField("description")
              .withTimestampField("rowtime")
              .build();
  
      // Create a concrete row with that type.
      Row row = Row.withRowType(appType)
              .addValues(1, "Some cool app", new Date())
              .build();
  
      // Create a source PCollection containing only that row
      PCollection&lt;Row&gt; testApps = PBegin
              .in(p)
              .apply(Create
                      .of(row)
                      .withCoder(appType.getRowCoder()));
  
      PCollection&lt;Row&gt; filteredNames = testApps.apply(
              BeamSql.query(
                      "SELECT appId, description, rowtime "
                              + "FROM PCOLLECTION "
                              + "WHERE appId=1"));
  }
  </code></pre>
  
  <p>This always fails with the following error:</p>
  
  <pre><code>java.lang.AssertionError
  at org.apache.beam.sdks.java.extensions.sql.repackaged.org.apache.calcite.plan.volcano.VolcanoPlanner.changeTraits(VolcanoPlanner.java:546)
  at org.apache.beam.sdks.java.extensions.sql.repackaged.org.apache.calcite.tools.Programs$RuleSetProgram.run(Programs.java:365)
  at org.apache.beam.sdks.java.extensions.sql.repackaged.org.apache.calcite.prepare.PlannerImpl.transform(PlannerImpl.java:336)
  at org.apache.beam.sdk.extensions.sql.impl.planner.BeamQueryPlanner.convertToBeamRel(BeamQueryPlanner.java:165)
  at org.apache.beam.sdk.extensions.sql.impl.planner.BeamQueryPlanner.validateAndConvert(BeamQueryPlanner.java:156)
  at org.apache.beam.sdk.extensions.sql.impl.planner.BeamQueryPlanner.convertToBeamRel(BeamQueryPlanner.java:144)
  at org.apache.beam.sdk.extensions.sql.QueryTransform.expand(QueryTransform.java:73)
  at org.apache.beam.sdk.extensions.sql.QueryTransform.expand(QueryTransform.java:47)
  at org.apache.beam.sdk.Pipeline.applyInternal(Pipeline.java:537)
  at org.apache.beam.sdk.Pipeline.applyTransform(Pipeline.java:472)
  at org.apache.beam.sdk.values.PCollection.apply(PCollection.java:286)
  at PipelineTest.dslTest(PipelineTest.java:42)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498)
  at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
  at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
  at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
  at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
  at org.apache.beam.sdk.testing.TestPipeline$1.evaluate(TestPipeline.java:324)
  at org.junit.rules.RunRules.evaluate(RunRules.java:20)
  at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
  at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
  at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
  at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
  at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
  at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
  at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
  </code></pre>
  
  <p>What is the correct way to run this test, or is this a bug and the dsl apis are not working?</p>