Do not flatten subqueries that are part of a compound SELECT and which

have both an ORDER BY and a LIMIT clause.  Ticket #2339. (CVS 3932)

FossilOrigin-Name: 9600a998043c6dd1d5ecb03d1ee9a9273910243d

test/tkt2339.test

@@ -0,0 +1,95 @@
+# 2007 May 6
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# $Id: tkt2339.test,v 1.1 2007/05/06 20:04:25 drh Exp $
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_test tkt2339.1 {
+  execsql {
+    create table t1(num int);
+    insert into t1 values (1);
+    insert into t1 values (2);
+    insert into t1 values (3);
+    insert into t1 values (4);
+    
+    create table t2(num int);
+    insert into t2 values (11);
+    insert into t2 values (12);
+    insert into t2 values (13);
+    insert into t2 values (14);
+    
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC LIMIT 2)
+    UNION
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC LIMIT 2)
+  }
+} {3 4 13 14}
+do_test tkt2339.2 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC LIMIT 2)
+    UNION ALL
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC LIMIT 2)
+  }
+} {4 3 14 13}
+do_test tkt2339.3 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC)
+    UNION ALL
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC LIMIT 2)
+  }
+} {4 3 2 1 14 13}
+do_test tkt2339.4 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC LIMIT 2)
+    UNION ALL
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC)
+  }
+} {4 3 14 13 12 11}
+do_test tkt2339.5 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC LIMIT 2)
+    UNION
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC)
+  }
+} {3 4 11 12 13 14}
+do_test tkt2339.6 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC LIMIT 2)
+    EXCEPT
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC)
+  }
+} {3 4}
+do_test tkt2339.7 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 LIMIT 2)
+    UNION
+    SELECT * FROM (SELECT * FROM t2 ORDER BY num DESC LIMIT 2)
+  }
+} {1 2 13 14}
+do_test tkt2339.8 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 LIMIT 2)
+    UNION
+    SELECT * FROM (SELECT * FROM t2 LIMIT 2)
+  }
+} {1 2 11 12}
+do_test tkt2339.9 {
+  execsql {
+    SELECT * FROM (SELECT * FROM t1 ORDER BY num DESC LIMIT 2)
+    UNION
+    SELECT * FROM (SELECT * FROM t2 LIMIT 2)
+  }
+} {3 4 11 12}
+
+
+finish_test