Merge pull request #765 from katzyn/selfref

Fix issue #710: Misleading exception message when INSERT has no value for self referential 'AS' column

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

@@ -186,9 +186,12 @@ public class ExpressionColumn extends Expression {
         }
         Value value = columnResolver.getValue(column);
         if (value == null) {
-            columnResolver.getValue(column);
+            if (select == null) {
+                throw DbException.get(ErrorCode.NULL_NOT_ALLOWED, getSQL());
+            } else {
                 throw DbException.get(ErrorCode.MUST_GROUP_BY_COLUMN_1, getSQL());
             }
+        }
         if (column.getEnumerators() != null && value != ValueNull.INSTANCE) {
             return ValueEnum.get(column.getEnumerators(), value.getInt());
         }

h2/src/test/org/h2/test/db/TestCases.java

@@ -51,6 +51,7 @@ public class TestCases extends TestBase {
         testLargeKeys();
         testExtraSemicolonInDatabaseURL();
         testGroupSubquery();
+        testSelfReferentialColumn();
         testCountDistinctNotNull();
         testDependencies();
         testDropTable();
@@ -234,6 +235,32 @@ public class TestCases extends TestBase {
         conn.close();
     }
 
+    private void testSelfReferentialColumn() throws SQLException {
+        deleteDb("selfreferential");
+        Connection conn = getConnection("selfreferential");
+        Statement stat = conn.createStatement();
+        stat.execute("create table sr(id integer, usecount integer as usecount + 1)");
+        check: {
+            try {
+                stat.execute("insert into sr(id) values (1)");
+            } catch (SQLException ex) {
+                assertEquals(ErrorCode.getState(ErrorCode.NULL_NOT_ALLOWED), ex.getSQLState());
+                break check;
+            }
+            fail("Exception expected");
+        }
+        check: {
+            try {
+                stat.execute("select max(id), usecount from sr");
+            } catch (SQLException ex) {
+                assertEquals(ErrorCode.getState(ErrorCode.MUST_GROUP_BY_COLUMN_1), ex.getSQLState());
+                break check;
+            }
+            fail("Exception expected");
+        }
+        conn.close();
+    }
+
     private void testCountDistinctNotNull() throws SQLException {
         deleteDb("cases");
         Connection conn = getConnection("cases");