#At file:///net/fimafeng09/export/home/tmp/oleja/mysql/mysql-5.1/ based on revid:georgi.kodinov@stripped
3477 Ole John Aske 2010-12-01
Fix for bug#58628: Incorrect result for 'WHERE NULL NOT IN (<subquery>)
create_ref_for_key() allowed any constant part of a REF key to be evaluated
and stored into the 'key_buff' during ::optimize(). These 'store_key*' was
*not* kept in ref.key_copy[] as they where constant and we assumed we
would not have to reevaluate them during JOIN::exec()
However, during execute NULL values in REF key has to be detected as they may
need special attention - as in 'Full scan on NULL key'. This is done by
subselect_uniquesubquery_engine::copy_ref_key() which check if any keyparts
evaluated to a NULL-value.
As we didn't keep a store_key for a constant value, a NULL-constant was not detected
by subselect_uniquesubquery_engine::copy_ref_key() !
This fixs modifies create_ref_for_key() to check if a NULL-value constant
was produced - In these cases it keeps the store_key, which then will be
reevaluated in JOIN::exec() and trigger correct handling of NULL-valued keys.
modified:
mysql-test/r/func_in.result
mysql-test/t/func_in.test
sql/sql_select.cc
sql/sql_select.h
=== modified file 'mysql-test/r/func_in.result'
--- a/mysql-test/r/func_in.result 2010-06-22 18:53:08 +0000
+++ b/mysql-test/r/func_in.result 2010-12-01 12:20:46 +0000
@@ -770,4 +770,40 @@ CASE a WHEN a THEN a END
NULL
DROP TABLE t1;
#
+# Bug#58628: Incorrect result for 'WHERE NULL NOT IN (<subquery>)
+#
+CREATE TABLE t1 (pk INT NOT NULL, i INT);
+INSERT INTO t1 VALUES (0,NULL), (1,NULL), (2,NULL), (3,NULL);
+CREATE TABLE subq (pk INT NOT NULL, i INT NOT NULL, PRIMARY KEY(i,pk));
+INSERT INTO subq VALUES (0,0), (1,1), (2,2), (3,3);
+SELECT * FROM t1
+WHERE t1.i NOT IN
+(SELECT i FROM subq WHERE subq.pk = t1.pk);
+pk i
+SELECT * FROM t1
+WHERE t1.i IN
+(SELECT i FROM subq WHERE subq.pk = t1.pk) IS UNKNOWN;
+pk i
+0 NULL
+1 NULL
+2 NULL
+3 NULL
+SELECT * FROM t1
+WHERE NULL NOT IN
+(SELECT i FROM subq WHERE subq.pk = t1.pk);
+pk i
+SELECT * FROM t1
+WHERE NULL IN
+(SELECT i FROM subq WHERE subq.pk = t1.pk) IS UNKNOWN;
+pk i
+0 NULL
+1 NULL
+2 NULL
+3 NULL
+SELECT * FROM t1
+WHERE 1+NULL NOT IN
+(SELECT i FROM subq WHERE subq.pk = t1.pk);
+pk i
+DROP TABLE t1,subq;
+#
End of 5.1 tests
=== modified file 'mysql-test/t/func_in.test'
--- a/mysql-test/t/func_in.test 2010-06-22 18:53:08 +0000
+++ b/mysql-test/t/func_in.test 2010-12-01 12:20:46 +0000
@@ -555,5 +555,50 @@ SELECT CASE a WHEN a THEN a END FROM t1
DROP TABLE t1;
--echo #
+--echo # Bug#58628: Incorrect result for 'WHERE NULL NOT IN (<subquery>)
+--echo #
+
+CREATE TABLE t1 (pk INT NOT NULL, i INT);
+INSERT INTO t1 VALUES (0,NULL), (1,NULL), (2,NULL), (3,NULL);
+
+CREATE TABLE subq (pk INT NOT NULL, i INT NOT NULL, PRIMARY KEY(i,pk));
+INSERT INTO subq VALUES (0,0), (1,1), (2,2), (3,3);
+
+## Baseline queries: t1.i contains only NULL and should effectively
+## be evaluated as 'WHERE NULL IN'
+## .. These return correct resultset !
+
+--sorted_result
+SELECT * FROM t1
+ WHERE t1.i NOT IN
+ (SELECT i FROM subq WHERE subq.pk = t1.pk);
+
+--sorted_result
+SELECT * FROM t1
+ WHERE t1.i IN
+ (SELECT i FROM subq WHERE subq.pk = t1.pk) IS UNKNOWN;
+
+## Replaced 't1.i' with some constant expression which
+## also evaluates to NULL. Expected to return same result as above:
+
+--sorted_result
+SELECT * FROM t1
+ WHERE NULL NOT IN
+ (SELECT i FROM subq WHERE subq.pk = t1.pk);
+
+--sorted_result
+SELECT * FROM t1
+ WHERE NULL IN
+ (SELECT i FROM subq WHERE subq.pk = t1.pk) IS UNKNOWN;
+
+--sorted_result
+SELECT * FROM t1
+ WHERE 1+NULL NOT IN
+ (SELECT i FROM subq WHERE subq.pk = t1.pk);
+
+
+DROP TABLE t1,subq;
+
+--echo #
--echo End of 5.1 tests
=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc 2010-10-29 08:23:06 +0000
+++ b/sql/sql_select.cc 2010-12-01 12:20:46 +0000
@@ -5798,22 +5798,36 @@ static bool create_ref_for_key(JOIN *joi
if (keyuse->null_rejecting)
j->ref.null_rejecting |= 1 << i;
keyuse_uses_no_tables= keyuse_uses_no_tables && !keyuse->used_tables;
- if (!keyuse->used_tables &&
- !(join->select_options & SELECT_DESCRIBE))
- { // Compare against constant
- store_key_item tmp(thd, keyinfo->key_part[i].field,
- key_buff + maybe_null,
- maybe_null ? key_buff : 0,
- keyinfo->key_part[i].length, keyuse->val);
- if (thd->is_fatal_error)
- DBUG_RETURN(TRUE);
- tmp.copy();
+
+ store_key* key= get_store_key(thd,
+ keyuse,join->const_table_map,
+ &keyinfo->key_part[i],
+ key_buff, maybe_null);
+ if (unlikely(!key || thd->is_fatal_error))
+ DBUG_RETURN(TRUE);
+
+ if (keyuse->used_tables || join->select_options & SELECT_DESCRIBE)
+ {
+ *ref_key++= key; // Always evaluate/explain in JOIN::exec()
}
else
- *ref_key++= get_store_key(thd,
- keyuse,join->const_table_map,
- &keyinfo->key_part[i],
- key_buff, maybe_null);
+ {
+ /* key is constant, copy value now and possibly skip it while ::exec() */
+ enum store_key::store_key_result result= key->copy();
+
+ /* Depending on 'result' it should be reevaluated in ::exec(), if either:
+ * 1) '::copy()' failed, in case we reevaluate - and refail in
+ * JOIN::exec() where the error can be handled.
+ * 2) Constant evaluated to NULL value which we might need to
+ * handle as a special case during JOIN::exec()
+ * (As in : 'Full scan on NULL key')
+ */
+ if (result!=store_key::STORE_KEY_OK || // 1)
+ key->null_key) // 2)
+ {
+ *ref_key++= key; // Reevaluate in JOIN::exec()
+ }
+ }
/*
Remember if we are going to use REF_OR_NULL
But only if field _really_ can be null i.e. we force JT_REF
=== modified file 'sql/sql_select.h'
--- a/sql/sql_select.h 2010-08-24 10:44:15 +0000
+++ b/sql/sql_select.h 2010-12-01 12:20:46 +0000
@@ -753,9 +753,8 @@ public:
store_key_const_item(THD *thd, Field *to_field_arg, uchar *ptr,
uchar *null_ptr_arg, uint length,
Item *item_arg)
- :store_key_item(thd, to_field_arg,ptr,
- null_ptr_arg ? null_ptr_arg : item_arg->maybe_null ?
- &err : (uchar*) 0, length, item_arg), inited(0)
+ :store_key_item(thd, to_field_arg, ptr,
+ null_ptr_arg, length, item_arg), inited(0)
{
}
const char *name() const { return "const"; }
@@ -763,23 +762,13 @@ public:
protected:
enum store_key_result copy_inner()
{
- int res;
if (!inited)
{
inited=1;
- if ((res= item->save_in_field(to_field, 1)))
- {
- if (!err)
- err= res < 0 ? 1 : res; /* 1=STORE_KEY_FATAL */
- }
- /*
- Item::save_in_field() may call Item::val_xxx(). And if this is a subquery
- we need to check for errors executing it and react accordingly
- */
- if (!err && to_field->table->in_use->is_error())
- err= 1; /* STORE_KEY_FATAL */
+ int res= store_key_item::copy_inner();
+ if (res && !err)
+ err= res;
}
- null_key= to_field->is_null() || item->null_value;
return (err > 2 ? STORE_KEY_FATAL : (store_key_result) err);
}
};
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