Optimize "(not) exists" exp on no-relationship path

agrestio · Feb 13, 2024 · 67fe671 · 67fe671
1 parent 95d9aaf
commit 67fe671
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diff --git a/agrest-cayenne/src/main/java/io/agrest/cayenne/exp/CayenneExpPostProcessor.java b/agrest-cayenne/src/main/java/io/agrest/cayenne/exp/CayenneExpPostProcessor.java
@@ -72,13 +72,28 @@ private Expression validateAndCleanup(ObjEntity entity, Expression exp) {
             exp = pathCache.resolve(entity.getName(), ((ASTObjPath) exp).getPath()).getPathExp();
         }
 
+        // process root ASTExits|ASTNotExists that can't be properly handled by ExpressionProcessor.
+        if (exp instanceof ASTExists || exp instanceof ASTNotExists) {
+            return optimizeExistsExp(exp);
+        }
+
         return exp;
     }
 
     private ExpressionProcessor getOrCreateExpressionProcessor(ObjEntity entity) {
         return postProcessors.computeIfAbsent(entity.getName(), e -> new ExpressionProcessor(entity));
     }
 
+    private static Expression optimizeExistsExp(Expression exp) {
+        Expression pathExistExp = ((Expression) exp.getOperand(0));
+        if (pathExistExp instanceof ASTSubquery) {
+            return exp;
+        }
+        return exp instanceof ASTExists
+                ? pathExistExp
+                : pathExistExp.notExp();
+    }
+
     private class ExpressionProcessor extends TraversalHelper {
 
         private final ObjEntity entity;
@@ -124,6 +139,9 @@ public void finishedChild(Expression parentNode, int childIndex, boolean hasMore
                         childIndex
                 );
             }
+            if (childNode instanceof ASTExists || childNode instanceof ASTNotExists) {
+                parentNode.setOperand(childIndex, optimizeExistsExp((Expression) childNode));
+            }
         }
 
         @Override

diff --git a/agrest-cayenne/src/test/java/io/agrest/cayenne/GET/ExpIT.java b/agrest-cayenne/src/test/java/io/agrest/cayenne/GET/ExpIT.java
@@ -404,6 +404,29 @@ public void exists_Path_Relationship() {
                 .bodyEquals(3, "{\"id\":1}", "{\"id\":2}", "{\"id\":3}");
     }
 
+    @Test
+    public void exists_Path_NoRelationship() {
+
+        tester.e2().insertColumns("id_", "name")
+                .values(1, "qwe")
+                .values(2, "try")
+                .exec();
+
+        tester.e3().insertColumns("id_", "name")
+                .values(1, "xxx")
+                .values(2, "yxy")
+                .values(3, null)
+                .exec();
+
+        tester.target("/e3")
+                .queryParam("include", "id")
+                .queryParam("exp", "exists name")
+                .queryParam("sort", "id")
+                .get()
+                .wasOk()
+                .bodyEquals(2, "{\"id\":1}", "{\"id\":2}");
+    }
+
     @Test
     public void like_MultiChar_Pattern_Escape() {