Fix determination of UNNEST data types for array constructors with casted parameters

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,11 @@ <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #4033: Wrong array produced when using ARRAY_AGG() on UNNEST(ARRAY[CAST(? AS INT)]) expression
+in a PreparedStatement
+</li>
+<li>Issue #3909: Maintenance taking too much resources since 2.2.222
+</li>
 <li>Issue #4010: org.h2.jdbc.JdbcConnection.getTypeMap() returns null
 </li>
 <li>PR #4007: Update pom.xml related to CVE-2024-1597

h2/src/main/org/h2/command/Parser.java

@@ -4414,12 +4414,8 @@ private ArrayTableFunction readUnnestFunction() {
             do {
                 Expression expr = readExpression();
                 TypeInfo columnType = TypeInfo.TYPE_NULL;
-                boolean constant = expr.isConstant();
-                if (constant || expr instanceof CastSpecification) {
-                    if (constant) {
-                        expr = expr.optimize(session);
-                    }
-                    TypeInfo exprType = expr.getType();
+                TypeInfo exprType = expr.getTypeIfStaticallyKnown(session);
+                if (exprType != null) {
                     switch (exprType.getValueType()) {
                     case Value.JSON:
                         columnType = TypeInfo.TYPE_JSON;

h2/src/main/org/h2/expression/Expression.java

@@ -284,6 +284,17 @@ public Expression getNotIfPossible(@SuppressWarnings("unused") SessionLocal sess
         return null;
     }
 
+    /**
+     * Returns data type of this expression if it is statically known.
+     *
+     * @param session
+     *            the session
+     * @return data type or {@code null}
+     */
+    public TypeInfo getTypeIfStaticallyKnown(SessionLocal session) {
+        return null;
+    }
+
     /**
      * Check if this expression will always return the same value.
      *

h2/src/main/org/h2/expression/ExpressionList.java

@@ -114,6 +114,21 @@ public int getCost() {
         return cost;
     }
 
+    @Override
+    public TypeInfo getTypeIfStaticallyKnown(SessionLocal session) {
+        int count = list.length;
+        TypeInfo[] types = new TypeInfo[count];
+        for (int i = 0; i < count; i++) {
+            TypeInfo t = list[i].getTypeIfStaticallyKnown(session);
+            if (t == null) {
+                return null;
+            }
+            types[i] = t;
+        }
+        return isArray ? TypeInfo.getTypeInfo(Value.ARRAY, list.length, 0, TypeInfo.getHigherType(types))
+                : TypeInfo.getTypeInfo(Value.ROW, 0, 0, new ExtTypeInfoRow(types));
+    }
+
     @Override
     public boolean isConstant() {
         for (Expression e : list) {

h2/src/main/org/h2/expression/Subquery.java

@@ -161,6 +161,16 @@ public int getCost() {
         return query.getCostAsExpression();
     }
 
+    @Override
+    public TypeInfo getTypeIfStaticallyKnown(SessionLocal session) {
+        if (query.isConstantQuery()) {
+            query.prepare();
+            setType();
+            return expression.getType();
+        }
+        return null;
+    }
+
     @Override
     public boolean isConstant() {
         return query.isConstantQuery();

h2/src/main/org/h2/expression/ValueExpression.java

@@ -114,6 +114,11 @@ public Expression getNotIfPossible(SessionLocal session) {
         return getBoolean(!value.getBoolean());
     }
 
+    @Override
+    public TypeInfo getTypeIfStaticallyKnown(SessionLocal session) {
+        return value.getType();
+    }
+
     @Override
     public boolean isConstant() {
         return true;

h2/src/main/org/h2/expression/function/CastSpecification.java

@@ -90,6 +90,11 @@ public Expression optimize(SessionLocal session) {
         return this;
     }
 
+    @Override
+    public TypeInfo getTypeIfStaticallyKnown(SessionLocal session) {
+        return type;
+    }
+
     @Override
     public boolean isConstant() {
         return left instanceof ValueExpression && (right == null || right.isConstant())

h2/src/test/org/h2/test/jdbc/TestPreparedStatement.java

@@ -1810,6 +1810,13 @@ private void testUnnestWithArrayParameter(Connection conn) throws SQLException {
             }
             assertFalse(rs.next());
         }
+        prep = conn.prepareStatement(
+                "SELECT ARRAY_AGG(V) FROM UNNEST(ARRAY[CAST(? AS INTEGER), CAST(? AS INTEGER)]) T(V)");
+        prep.setInt(1, 1);
+        prep.setInt(2, 2);
+        ResultSet rs = prep.executeQuery();
+        assertTrue(rs.next());
+        assertEquals(new Integer[] { 1, 2 }, rs.getObject(1, Integer[].class));
     }
 
 }