From: Date: September 8 2007 6:23pm
Subject: bk commit into 5.0 tree (sergefp:1.2513) BUG#30324
List-Archive: http://lists.mysql.com/commits/33963
X-Bug: 30324
Message-Id: <20070908162356.EC1E8FBC15@pylon.mylan>

Below is the list of changes that have just been committed into a local
5.0 repository of psergey. When psergey does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2007-09-08 20:23:52+04:00, sergefp@stripped +3 -0
  BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
  - The bug was caused by COUNT(DISTINCT ...) code using Unique object in 
    a way that assumed that BIT(N) column occupies a continous space in
    temp_table->record[0] buffer. 
  - The fix is to make COUNT(DISTINCT ...) code instruct create_tmp_table to
    create temporary table with column of type BIGINT, not BIT(N).

  mysql-test/r/type_bit.result@stripped, 2007-09-08 20:23:49+04:00, sergefp@stripped +15 -0
    BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
    - Testcase

  mysql-test/t/type_bit.test@stripped, 2007-09-08 20:23:49+04:00, sergefp@stripped +14 -0
    BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
    - Testcase

  sql/item_sum.cc@stripped, 2007-09-08 20:23:49+04:00, sergefp@stripped +17 -0
    BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
    - Make COUNT(DISTINCT ...) code instruct create_tmp_table to create 
      temporary table with BIGINT, not BIT(N) column.

diff -Nrup a/mysql-test/r/type_bit.result b/mysql-test/r/type_bit.result
--- a/mysql-test/r/type_bit.result	2007-08-17 18:29:10 +04:00
+++ b/mysql-test/r/type_bit.result	2007-09-08 20:23:49 +04:00
@@ -657,4 +657,19 @@ b
 #
 #
 DROP TABLE t1;
+CREATE TABLE t1 (a int, b bit(2));
+INSERT INTO t1 VALUES (3, 2), (2, 3), (2, 0), (3, 2), (3, 1);
+SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
+COUNT(DISTINCT b)
+2
+2
+DROP TABLE t1;
+create table t2 (a int, b bit(2), c char(10));
+INSERT INTO t2 VALUES (3, 2, 'two'), (2, 3, 'three'), (2, 0, 'zero'), 
+(3, 2, 'two'), (3, 1, 'one');
+SELECT COUNT(DISTINCT b,c) FROM t2 GROUP BY a;
+COUNT(DISTINCT b,c)
+2
+2
+DROP TABLE t2;
 End of 5.0 tests
diff -Nrup a/mysql-test/t/type_bit.test b/mysql-test/t/type_bit.test
--- a/mysql-test/t/type_bit.test	2007-08-17 18:28:48 +04:00
+++ b/mysql-test/t/type_bit.test	2007-09-08 20:23:49 +04:00
@@ -304,4 +304,18 @@ SELECT b FROM t1 GROUP BY b;
 --disable_metadata
 DROP TABLE t1;
 
+#
+# BUG#30324 Wrong query result for COUNT(DISTINCT(bit_column))
+#
+CREATE TABLE t1 (a int, b bit(2));
+INSERT INTO t1 VALUES (3, 2), (2, 3), (2, 0), (3, 2), (3, 1);
+SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
+DROP TABLE t1;
+
+create table t2 (a int, b bit(2), c char(10));
+INSERT INTO t2 VALUES (3, 2, 'two'), (2, 3, 'three'), (2, 0, 'zero'), 
+                      (3, 2, 'two'), (3, 1, 'one');
+SELECT COUNT(DISTINCT b,c) FROM t2 GROUP BY a;
+DROP TABLE t2;
+
 --echo End of 5.0 tests
diff -Nrup a/sql/item_sum.cc b/sql/item_sum.cc
--- a/sql/item_sum.cc	2007-07-19 20:20:54 +04:00
+++ b/sql/item_sum.cc	2007-09-08 20:23:49 +04:00
@@ -2464,6 +2464,23 @@ bool Item_sum_count_distinct::setup(THD 
   count_field_types(select_lex, tmp_table_param, list, 0);
   tmp_table_param->force_copy_fields= force_copy_fields;
   DBUG_ASSERT(table == 0);
+  /*
+    Make create_tmp_table() convert BIT columns to BIGINT.
+    This is needed because BIT fields store parts of their data in table's
+    null bits, and we don't have methods to compare two table records, which
+    is needed by Unique which is used when HEAP table is used.
+  */
+  {
+    List_iterator_fast<Item> li(list);
+    Item *item;
+    while ((item= li++))
+    {
+      if (item->type() == Item::FIELD_ITEM &&
+          ((Item_field*)item)->field->type() == FIELD_TYPE_BIT)
+        item->marker=4;
+    }
+  }
+
   if (!(table= create_tmp_table(thd, tmp_table_param, list, (ORDER*) 0, 1,
 				0,
 				(select_lex->options | thd->options),