Hello,
When I am using case when statement in flink sql, I got an error as follow: org.apache.flink.table.planner.codegen.CodeGenException: Unable to find common type of GeneratedExpression(field$3,isNull$3,,INT,None) and ArrayBuffer(GeneratedExpression(((org.apache.flink.table.data.binary.BinaryStringData) str$4),false,,CHAR(0) NOT NULL,Some()), GeneratedExpression(((org.apache.flink.table.data.binary.BinaryStringData) str$5),false,,CHAR(1) NOT NULL,Some(0))). at org.apache.flink.table.planner.codegen.calls.ScalarOperatorGens$.$anonfun$generateIn$2(ScalarOperatorGens.scala:354) at scala.Option.orElse(Option.scala:289) at org.apache.flink.table.planner.codegen.calls.ScalarOperatorGens$.generateIn(ScalarOperatorGens.scala:354) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.generateCallExpression(ExprCodeGenerator.scala:724) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.visitCall(ExprCodeGenerator.scala:507) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.visitCall(ExprCodeGenerator.scala:56) at org.apache.calcite.rex.RexCall.accept(RexCall.java:174) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.$anonfun$visitCall$2(ExprCodeGenerator.scala:526) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:233) at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:58) at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:51) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at scala.collection.TraversableLike.map(TraversableLike.scala:233) at scala.collection.TraversableLike.map$(TraversableLike.scala:226) at scala.collection.AbstractTraversable.map(Traversable.scala:104) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.visitCall(ExprCodeGenerator.scala:517) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.visitCall(ExprCodeGenerator.scala:56) at org.apache.calcite.rex.RexCall.accept(RexCall.java:174) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.$anonfun$visitCall$2(ExprCodeGenerator.scala:526) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:233) at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:58) at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:51) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at scala.collection.TraversableLike.map(TraversableLike.scala:233) at scala.collection.TraversableLike.map$(TraversableLike.scala:226) at scala.collection.AbstractTraversable.map(Traversable.scala:104) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.visitCall(ExprCodeGenerator.scala:517) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.visitCall(ExprCodeGenerator.scala:56) at org.apache.calcite.rex.RexCall.accept(RexCall.java:174) at org.apache.flink.table.planner.codegen.ExprCodeGenerator.generateExpression(ExprCodeGenerator.scala:155) at org.apache.flink.table.planner.codegen.CalcCodeGenerator$.$anonfun$generateProcessCode$4(CalcCodeGenerator.scala:141) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:233) at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:58) at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:51) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at scala.collection.TraversableLike.map(TraversableLike.scala:233) at scala.collection.TraversableLike.map$(TraversableLike.scala:226) at scala.collection.AbstractTraversable.map(Traversable.scala:104) ...... My SQL is create table source_tb ( a varchar, b INTEGER ) with ( 'connector' = 'kafka', ... ); create table sink_tb ( a varchar, c varchar ) with ( 'connector' = 'console', 'format' = 'rich-json' ); insert into sink_tb(a, c) select a, case when b is null or b = '' or b = '0' then '1000-01-01 00:00:00' else from_unixtime(cast(b as bigint)) end as c from source_tb; But it works well when I change the when statement to b is null or b in ('', '0') Does anyone have idea about this ?