From: Date: April 26 2006 9:39am Subject: bk commit into 4.1 tree (gkodinov:1.2459) BUG#18492 List-Archive: http://lists.mysql.com/commits/5548 X-Bug: 18492 Message-Id: <200604260739.k3Q7d3XQ006941@rakia.progem.bg> Below is the list of changes that have just been committed into a local 4.1 repository of kgeorge. When kgeorge 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 1.2459 06/04/26 10:38:59 gkodinov@stripped +6 -0 BUG#18492: mysqld reports ER_ILLEGAL_REFERENCE in --ps-protocol In the code that converts IN predicates to EXISTS predicates it is changing the select list elements to constant 1. Example : SELECT ... FROM ... WHERE a IN (SELECT c FROM ...) is transformed to : SELECT ... FROM ... WHERE EXISTS (SELECT 1 FROM ... HAVING a = c) However there can no FROM clause in the IN subquery and it may not be a simple select : SELECT ... FROM ... WHERE a IN (SELECT f(..) AS c UNION SELECT ...) This query is transformed to : SELECT ... FROM ... WHERE EXISTS (SELECT 1 FROM (SELECT f(..) AS c UNION SELECT ...) x HAVING a = c) In the above query the c in the HAVING clause is made to be an Item_null_helper (a subclass of Item_ref) pointing to the real Item_field (witch is not referenced anywhere else in the query anymore). This is done because Item_ref_null_helper collects information whether there are NULL values in the result. This is OK for directly executed statements, because the Item_field pointed by the Item_null_helper is already fixed when the transformation is done. But when executed as a prepared statement all the Item instances are "un-fixed" before the recompilation of the prepared statement. So when the Item_null_helper gets fixed it discovers that the Item_field it points to is not fixed and issues an error. The remedy is to keep the original select list references when there are no tables in the FROM clause. So the above becomes : SELECT ... FROM ... WHERE EXISTS (SELECT c FROM (SELECT f(..) AS c UNION SELECT ...) x HAVING a = c) In this way the c is referenced directly in the select list as well as by reference in the HAVING clause. So it gets correctly fixed even with prepared statements. And since the Item_null_helper subclass of Item_ref_null_helper is not used anywhere else it's taken out. sql/item_subselect.cc 1.140 06/04/26 10:38:55 gkodinov@stripped +9 -7 The described change to the IN->EXISTS transformation sql/item.h 1.193 06/04/26 10:38:55 gkodinov@stripped +0 -13 Taking out the Item_null_helper as it's no longer needed sql/item.cc 1.232 06/04/26 10:38:55 gkodinov@stripped +0 -8 Taking out the Item_null_helper as it's no longer needed mysql-test/t/ps_11bugs.test 1.6 06/04/26 10:38:55 gkodinov@stripped +14 -0 Testcase for the bug mysql-test/r/subselect.result 1.175 06/04/26 10:38:55 gkodinov@stripped +1 -1 Explain updated because of the tranformation mysql-test/r/ps_11bugs.result 1.4 06/04/26 10:38:55 gkodinov@stripped +14 -0 Test case for the bug # This is a BitKeeper patch. What follows are the unified diffs for the # set of deltas contained in the patch. The rest of the patch, the part # that BitKeeper cares about, is below these diffs. # User: gkodinov # Host: rakia.progem.bg # Root: /home/kgeorge/mysql/4.1/B18492 --- 1.231/sql/item.cc 2006-03-01 15:53:13 +02:00 +++ 1.232/sql/item.cc 2006-04-26 10:38:55 +03:00 @@ -2716,14 +2716,6 @@ } -void Item_null_helper::print(String *str) -{ - str->append("(", 14); - store->print(str); - str->append(')'); -} - - bool Item_default_value::eq(const Item *item, bool binary_cmp) const { return item->type() == DEFAULT_VALUE_ITEM && --- 1.192/sql/item.h 2005-10-12 23:27:47 +03:00 +++ 1.193/sql/item.h 2006-04-26 10:38:55 +03:00 @@ -1045,19 +1045,6 @@ } }; -class Item_null_helper :public Item_ref_null_helper -{ - Item *store; -public: - Item_null_helper(Item_in_subselect* master, Item *item, - const char *table_name_par, const char *field_name_par) - :Item_ref_null_helper(master, &item, table_name_par, field_name_par), - store(item) - { ref= &store; } - void print(String *str); -}; - - /* The following class is used to optimize comparing of date and bigint columns We need to save the original item ('ref') to be able to call --- 1.174/mysql-test/r/subselect.result 2005-10-15 17:46:09 +03:00 +++ 1.175/mysql-test/r/subselect.result 2006-04-26 10:38:55 +03:00 @@ -734,7 +734,7 @@ 3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used NULL UNION RESULT ALL NULL NULL NULL NULL NULL Warnings: -Note 1003 select test.t2.id AS `id` from test.t2 where (test.t2.id,(select 1 AS `Not_used` having ((test.t2.id) = (1)) union select 1 AS `Not_used` having ((test.t2.id) = (3)))) +Note 1003 select test.t2.id AS `id` from test.t2 where (test.t2.id,(select 1 AS `1` having ((test.t2.id) = (1)) union select 3 AS `3` having ((test.t2.id) = (3)))) SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 3); id SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 2); --- 1.139/sql/item_subselect.cc 2005-08-13 07:45:07 +03:00 +++ 1.140/sql/item_subselect.cc 2006-04-26 10:38:55 +03:00 @@ -822,13 +822,13 @@ } else { - select_lex->item_list.empty(); - select_lex->item_list.push_back(new Item_int("Not_used", - (longlong) 1, 21)); - select_lex->ref_pointer_array[0]= select_lex->item_list.head(); if (select_lex->table_list.elements) { Item *having= item, *orig_item= item; + select_lex->item_list.empty(); + select_lex->item_list.push_back(new Item_int("Not_used", + (longlong) 1, 21)); + select_lex->ref_pointer_array[0]= select_lex->item_list.head(); item= func->create(expr, item); if (!abort_on_null && orig_item->maybe_null) { @@ -875,9 +875,11 @@ select_lex->having= join->having= func->create(expr, - new Item_null_helper(this, item, - (char *)"", - (char *)"")); + new Item_ref_null_helper(this, + select_lex->ref_pointer_array, + (char *)"", + (char *)"")); + select_lex->having_fix_field= 1; if (join->having->fix_fields(thd, join->tables_list, 0)) --- 1.3/mysql-test/r/ps_11bugs.result 2004-10-15 13:56:54 +03:00 +++ 1.4/mysql-test/r/ps_11bugs.result 2006-04-26 10:38:55 +03:00 @@ -116,3 +116,17 @@ cola colb cold aaaa yyyy R drop table t1, t2; +create table t1 (a int primary key); +insert into t1 values (1); +explain select * from t1 where 3 in (select (1+1) union select 1); +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables +2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL No tables used +3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used +NULL UNION RESULT ALL NULL NULL NULL NULL NULL +select * from t1 where 3 in (select (1+1) union select 1); +a +prepare st_18492 from 'select * from t1 where 3 in (select (1+1) union select 1)'; +execute st_18492; +a +drop table t1; --- 1.5/mysql-test/t/ps_11bugs.test 2005-07-28 03:21:46 +03:00 +++ 1.6/mysql-test/t/ps_11bugs.test 2006-04-26 10:38:55 +03:00 @@ -130,3 +130,17 @@ # end of bug#1676 # End of 4.1 tests + +# bug#18492: mysqld reports ER_ILLEGAL_REFERENCE in --ps-protocol + +create table t1 (a int primary key); +insert into t1 values (1); + +explain select * from t1 where 3 in (select (1+1) union select 1); + +select * from t1 where 3 in (select (1+1) union select 1); + +prepare st_18492 from 'select * from t1 where 3 in (select (1+1) union select 1)'; +execute st_18492; + +drop table t1;