MONDRIAN: Add unit test for Dialect.allowsSelectNotInGroupBy.

[git-p4: depot-paths = "//open/mondrian/": change = 12923]

src/main/mondrian/spi/Dialect.java

@@ -663,9 +663,19 @@ boolean supportsResultSetConcurrency(
     boolean allowsDialectSharing();
 
     /**
-     * Returns whether the database currently permits queries to
-     * SELECT columns that are not listed in the GROUP BY clause.
-     * Most don't, MySQL is an example of one that does.
+     * Returns whether the database currently permits queries to include in the
+     * SELECT clause expressions that are not listed in the GROUP BY clause. The
+     * SQL standard allows this if the database can deduce that the expression
+     * is functionally dependent on columns in the GROUP BY clause.
+     *
+     * <p>For example, {@code SELECT empno, first_name || ' ' || last_name FROM
+     * emps GROUP BY empno} is valid because {@code empno} is the primary key of
+     * the {@code emps} table, and therefore all columns are dependent on it.
+     * For a given value of {@code empno},
+     * {@code first_name || ' ' || last_name} has a unique value.
+     *
+     * <p>Most databases do not, MySQL is an example of one that does (if the
+     * functioality is enabled).
      *
      * @return Whether this Dialect allows SELECT clauses to contain
      * columns that are not in the GROUP BY clause

src/main/mondrian/spi/impl/JdbcDialectImpl.java

@@ -759,7 +759,7 @@ public boolean requiresUnionOrderByOrdinal() {
     }
 
     public boolean requiresUnionOrderByExprToBeInSelectClause() {
-        return false;
+        return true;
     }
 
     public boolean supportsMultiValueInExpr() {

testsrc/main/mondrian/test/DialectTest.java

@@ -369,6 +369,10 @@ public void testRequiresUnionOrderByExprToBeInSelectClause() {
                 + "includes fields that are not selected by the query\\.  "
                 + "Only those fields requested in the first query can be "
                 + "included in an ORDER BY expression\\.",
+                // derby (yes, lame message)
+                "Java exception: ': java.lang.NullPointerException'.",
+                // oracle
+                "ORA-01785: ORDER BY item must be the number of a SELECT-list expression\n",
             };
             assertQueryFails(sql, errs);
         }
@@ -383,11 +387,11 @@ public void testSupportsGroupByExpressions() {
         if (getDialect().supportsGroupByExpressions()) {
             assertQuerySucceeds(sql);
         } else {
-            assertQueryFails(
-                sql,
-                new String[] {
-                    "'sum\\(`unit_sales` \\+ 3\\) \\+ 8' isn't in GROUP BY"
-                });
+            final String[] errs = {
+                // mysql
+                "'sum\\(`unit_sales` \\+ 3\\) \\+ 8' isn't in GROUP BY",
+            };
+            assertQueryFails(sql, errs);
         }
     }
 
@@ -739,7 +743,7 @@ protected void assertQueryFails(String sql, String[] patterns) {
                 }
                 throw new AssertionFailedError(
                     "error [" + message
-                        + "] did not match any of the supplied patterns");
+                    + "] did not match any of the supplied patterns");
             }
             assertTrue(resultSet.next());
             Object col1 = resultSet.getObject(1);
@@ -756,6 +760,42 @@ protected void assertQueryFails(String sql, String[] patterns) {
             }
         }
     }
+
+    /**
+     * Unit test for {@link Dialect#allowsSelectNotInGroupBy}.
+     */
+    public void testAllowsSelectNotInGroupBy() throws SQLException {
+        Dialect dialect = getDialect();
+        String sql =
+            "select "
+            + dialect.quoteIdentifier("time_id")
+            + ", "
+            + dialect.quoteIdentifier("the_month")
+            + " from "
+            + dialect.quoteIdentifier("time_by_day")
+            + " group by "
+            + dialect.quoteIdentifier("time_id");
+        if (dialect.allowsSelectNotInGroupBy()) {
+            final ResultSet resultSet =
+                getConnection().createStatement().executeQuery(sql);
+            assertTrue(resultSet.next());
+            resultSet.close();
+        } else {
+            String[] errs = {
+                // oracle
+                "ORA-00979: not a GROUP BY expression\n",
+                // derby
+                "The SELECT list of a grouped query contains at least one "
+                + "invalid expression. If a SELECT list has a GROUP BY, the "
+                + "list may only contain valid grouping expressions and valid "
+                + "aggregate expressions.  ",
+                // mysql (if sql_mode contains ONLY_FULL_GROUP_BY)
+                "ERROR 1055 (42000): 'foodmart.time_by_day.the_month' isn't in "
+                + "GROUP BY",
+            };
+            assertQueryFails(sql, errs);
+        }
+    }
 }
 
 // End DialectTest.java