fix: Ensure correct evaluation order in BinaryColumnTransformer

Author: FearfulTomcat27

integration-test/src/test/java/org/apache/iotdb/db/it/query/IoTDBCaseWhenThenIT.java

@@ -919,4 +919,13 @@ public void testMultipleSatisfyCase() {
         };
     resultSetEqualTest(sql, expectedHeader, retArray);
   }
+
+  @Test
+  public void testThenWithBinarySameConstant() {
+    String sql = "SELECT CASE WHEN true THEN 200 + (s1 - 200) END AS result FROM root.sg.d1";
+    String[] expectedHeader = new String[] {TIMESTAMP_STR, "result"};
+    String[] retArray =
+        new String[] {"0,0.0,", "1000000,11.0,", "20000000,22.0,", "210000000,33.0,"};
+    resultSetEqualTest(sql, expectedHeader, retArray);
+  }
 }

integration-test/src/test/java/org/apache/iotdb/relational/it/db/it/IoTDBCaseWhenThenTableIT.java

@@ -673,4 +673,12 @@ public void testKind1Logic() {
     String[] retArray = new String[] {"null,", "just so so~~~,", "null,", "very well~~~,"};
     tableResultSetEqualTest(sql, expectedHeader, retArray, DATABASE);
   }
+
+  @Test
+  public void testThenWithBinarySameConstant() {
+    String sql = "SELECT CASE WHEN true THEN 200 + (s1 - 200) END AS result FROM table1";
+    String[] expectedHeader = new String[] {"result"};
+    String[] retArray = new String[] {"0,", "11,", "22,", "33,"};
+    tableResultSetEqualTest(sql, expectedHeader, retArray, DATABASE);
+  }
 }

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/transformation/dag/column/binary/BinaryColumnTransformer.java

@@ -56,10 +56,12 @@ public void evaluate() {
   @Override
   public void evaluateWithSelection(boolean[] selection) {
     leftTransformer.evaluateWithSelection(selection);
-    rightTransformer.evaluateWithSelection(selection);
     // attention: get positionCount before calling getColumn
     int positionCount = leftTransformer.getColumnCachePositionCount();
     Column leftColumn = leftTransformer.getColumn();
+    // When the rightTransformer has the same constant as the leftTransformer, the leftTransformer's
+    // cache will be cleared, so need to getColumn before evaluate rightTransformer.
+    rightTransformer.evaluateWithSelection(selection);
     Column rightColumn = rightTransformer.getColumn();
 
     ColumnBuilder builder = returnType.createColumnBuilder(positionCount);

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/transformation/dag/column/multi/MultiColumnTransformer.java

@@ -25,6 +25,7 @@
 import org.apache.tsfile.block.column.ColumnBuilder;
 import org.apache.tsfile.read.common.type.Type;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -60,20 +61,17 @@ public void evaluate() {
 
   @Override
   public void evaluateWithSelection(boolean[] selection) {
+    List<Column> childrenColumns = new ArrayList<>();
+
     for (ColumnTransformer child : columnTransformerList) {
       child.evaluateWithSelection(selection);
+      childrenColumns.add(child.getColumn());
     }
 
     int positionCount = columnTransformerList.get(0).getColumnCachePositionCount();
 
     ColumnBuilder builder = returnType.createColumnBuilder(positionCount);
-    doTransform(
-        columnTransformerList.stream()
-            .map(ColumnTransformer::getColumn)
-            .collect(Collectors.toList()),
-        builder,
-        positionCount,
-        selection);
+    doTransform(childrenColumns, builder, positionCount, selection);
     initializeColumnCache(builder.build());
 
     for (ColumnTransformer child : columnTransformerList) {