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MDEV-8705 Wrong result for SELECT..WHERE latin1_bin_column='a' AND latin1_bin_column='A'

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MDEV-8712 Wrong result for SELECT..WHERE latin1_bin_column=_latin1'a' AND latin1_bin_column='A'
This commit is contained in:
Alexander Barkov
2015-09-11 09:20:40 +04:00
parent 4aebba3aeb
commit 0302efca7f
7 changed files with 132 additions and 40 deletions
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19
mysql-test/r/ctype_latin1.result
View File

@ -8149,5 +8149,24 @@ Warnings:
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` = 'a') and (length(`test`.`t1`.`a`) = 2))
DROP TABLE t1;
#
# MDEV-8712 Wrong result for SELECT..WHERE latin1_bin_column=_latin1'a' AND latin1_bin_column='A'
#
SET NAMES latin1;
CREATE TABLE t1 (a VARCHAR(20) COLLATE latin1_bin);
INSERT INTO t1 VALUES ('a'),('b');
SELECT * FROM t1 WHERE a='A';
a
SELECT * FROM t1 WHERE a='A' AND a=_latin1'a';
a
SELECT * FROM t1 WHERE a=_latin1'a' AND a='A';
a
SELECT * FROM t1 WHERE a=_latin1'A';
a
SELECT * FROM t1 WHERE a=_latin1'A' AND a=_latin1'a';
a
SELECT * FROM t1 WHERE a=_latin1'a' AND a=_latin1'A';
a
DROP TABLE t1;
#
# End of 10.1 tests
#

17
mysql-test/r/ctype_uca.result
View File

@ -13709,5 +13709,22 @@ SELECT '10' COLLATE utf8_general_ci XOR '20' COLLATE utf8_unicode_ci;
'10' COLLATE utf8_general_ci XOR '20' COLLATE utf8_unicode_ci
0
#
# MDEV-8705 Wrong result for SELECT..WHERE latin1_bin_column='a' AND latin1_bin_column='A'
#
SET NAMES utf8 COLLATE utf8_german2_ci;
CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET utf8 COLLATE utf8_bin);
INSERT INTO t1 VALUES ('a'),('A');
SELECT * FROM t1 WHERE a='a';
a
a
SELECT * FROM t1 WHERE a=_utf8'a';
a
a
SELECT * FROM t1 WHERE a='a' AND a=_utf8'a';
a
a
DROP TABLE t1;
SET NAMES utf8;
#
# End of MariaDB-10.1 tests
#

13
mysql-test/t/ctype_latin1.test
View File

@ -349,6 +349,19 @@ SELECT * FROM t1 WHERE a='a' AND LENGTH(a)=2;
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='a' AND LENGTH(a)=2;
DROP TABLE t1;
--echo #
--echo # MDEV-8712 Wrong result for SELECT..WHERE latin1_bin_column=_latin1'a' AND latin1_bin_column='A'
--echo #
SET NAMES latin1;
CREATE TABLE t1 (a VARCHAR(20) COLLATE latin1_bin);
INSERT INTO t1 VALUES ('a'),('b');
SELECT * FROM t1 WHERE a='A';
SELECT * FROM t1 WHERE a='A' AND a=_latin1'a';
SELECT * FROM t1 WHERE a=_latin1'a' AND a='A';
SELECT * FROM t1 WHERE a=_latin1'A';
SELECT * FROM t1 WHERE a=_latin1'A' AND a=_latin1'a';
SELECT * FROM t1 WHERE a=_latin1'a' AND a=_latin1'A';
DROP TABLE t1;
--echo #
--echo # End of 10.1 tests

12
mysql-test/t/ctype_uca.test
View File

@ -630,6 +630,18 @@ DROP TABLE t1;
--echo #
SELECT '10' COLLATE utf8_general_ci XOR '20' COLLATE utf8_unicode_ci;
--echo #
--echo # MDEV-8705 Wrong result for SELECT..WHERE latin1_bin_column='a' AND latin1_bin_column='A'
--echo #
SET NAMES utf8 COLLATE utf8_german2_ci;
CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET utf8 COLLATE utf8_bin);
INSERT INTO t1 VALUES ('a'),('A');
SELECT * FROM t1 WHERE a='a';
SELECT * FROM t1 WHERE a=_utf8'a';
# Make sure this does not return "Illegal mix of collations"
SELECT * FROM t1 WHERE a='a' AND a=_utf8'a';
DROP TABLE t1;
SET NAMES utf8;
--echo #
--echo # End of MariaDB-10.1 tests

98
sql/item_cmpfunc.cc
View File

@ -5920,7 +5920,7 @@ Item_equal::Item_equal(THD *thd, Item *f1, Item *f2, bool with_const_item):
with_const= with_const_item;
equal_items.push_back(f1, thd->mem_root);
equal_items.push_back(f2, thd->mem_root);
compare_as_dates= with_const_item && f2->cmp_type() == TIME_RESULT;
cmp.cmp_collation.set(f2->collation);
cmp.set_compare_type(item_cmp_type(f1, f2));
upper_levels= NULL;
}
@ -5950,7 +5950,7 @@ Item_equal::Item_equal(THD *thd, Item_equal *item_equal):
equal_items.push_back(item, thd->mem_root);
}
with_const= item_equal->with_const;
compare_as_dates= item_equal->compare_as_dates;
cmp.cmp_collation.set(item_equal->cmp.cmp_collation);
cmp.set_compare_type(item_equal->cmp.compare_type());
cond_false= item_equal->cond_false;
upper_levels= item_equal->upper_levels;
@ -5971,41 +5971,85 @@ Item_equal::Item_equal(THD *thd, Item_equal *item_equal):
the list. Otherwise the value of c is compared with the value of the
constant item from equal_items. If they are not equal cond_false is set
to TRUE. This serves as an indicator that this Item_equal is always FALSE.
The optional parameter f is used to adjust the flag compare_as_dates.
*/
void Item_equal::add_const(THD *thd, Item *c, Item *f)
void Item_equal::add_const(THD *thd, Item *c)
{
if (cond_false)
return;
if (!with_const)
{
with_const= TRUE;
if (f)
compare_as_dates= f->cmp_type() == TIME_RESULT;
equal_items.push_front(c, thd->mem_root);
return;
}
Item *const_item= get_const();
if (compare_as_dates)
{
cmp.set_datetime_cmp_func(this, &c, &const_item);
cond_false= cmp.compare();
}
else
{
Item_func_eq *func= new (thd->mem_root) Item_func_eq(thd, c, const_item);
if (func->set_cmp_func())
switch (cmp.compare_type()) {
case TIME_RESULT:
{
/*
Setting a comparison function fails when trying to compare
incompatible charsets. Charset compatibility is checked earlier,
except for constant subqueries where we may do it here.
*/
return;
cmp.set_datetime_cmp_func(this, &c, &const_item);
cond_false= cmp.compare();
break;
}
case STRING_RESULT:
{
String *str1, *str2;
/*
Suppose we have an expression (with a string type field) like this:
WHERE field=const1 AND field=const2 ...
For all pairs field=constXXX we know that:
- Item_func_eq::fix_length_and_dec() performed collation and character
set aggregation and added character set converters when needed.
Note, the case like:
WHERE field=const1 COLLATE latin1_bin AND field=const2
is not handled here, because the field would be replaced to
Item_func_set_collation, which cannot get into Item_equal.
So all constXXX that are handled by Item_equal
already have compatible character sets with "field".
- Also, Field_str::test_if_equality_guarantees_uniqueness() guarantees
that the comparison collation of all equalities handled by Item_equal
match the the collation of the field.
Therefore, at Item_equal::add_const() time all constants constXXX
should be directly comparable to each other without an additional
character set conversion.
It's safe to do val_str() for "const_item" and "c" and compare
them according to the collation of the *field*.
So in a script like this:
CREATE TABLE t1 (a VARCHAR(10) COLLATE xxx);
INSERT INTO t1 VALUES ('a'),('A');
SELECT * FROM t1 WHERE a='a' AND a='A';
Item_equal::add_const() effectively rewrites the condition to:
SELECT * FROM t1 WHERE a='a' AND 'a' COLLATE xxx='A';
and then to:
SELECT * FROM t1 WHERE a='a'; // if the two constants were equal
// e.g. in case of latin1_swedish_ci
or to:
SELECT * FROM t1 WHERE FALSE; // if the two constants were not equal
// e.g. in case of latin1_bin
Note, both "const_item" and "c" can return NULL, e.g.:
SELECT * FROM t1 WHERE a=NULL AND a='const';
SELECT * FROM t1 WHERE a='const' AND a=NULL;
SELECT * FROM t1 WHERE a='const' AND a=(SELECT MAX(a) FROM t2)
*/
cond_false= !(str1= const_item->val_str(&cmp.value1)) ||
!(str2= c->val_str(&cmp.value2)) ||
!str1->eq(str2, compare_collation());
break;
}
default:
{
Item_func_eq *func= new (thd->mem_root) Item_func_eq(thd, c, const_item);
if (func->set_cmp_func())
return;
func->quick_fix_field();
cond_false= !func->val_int();
}
func->quick_fix_field();
cond_false= !func->val_int();
}
if (with_const && equal_items.elements == 1)
cond_true= TRUE;
@ -6482,14 +6526,6 @@ void Item_equal::print(String *str, enum_query_type query_type)
}
CHARSET_INFO *Item_equal::compare_collation() const
{
Item_equal_fields_iterator it(*((Item_equal*) this));
Item *item= it++;
return item->collation.collation;
}
/*
@brief Get the first equal field of multiple equality.
@param[in] field the field to get equal field to

11
sql/item_cmpfunc.h
View File

@ -2052,12 +2052,6 @@ class Item_equal: public Item_bool_func
the equal_items should be ignored.
*/
bool cond_true;
/*
compare_as_dates=TRUE <-> constants equal to fields from equal_items
must be compared as datetimes and not as strings.
compare_as_dates can be TRUE only if with_const=TRUE
*/
bool compare_as_dates;
/*
The comparator used to compare constants equal to fields from equal_items
as datetimes. The comparator is used only if compare_as_dates=TRUE
@ -2080,7 +2074,7 @@ public:
Item_equal(THD *thd, Item_equal *item_equal);
/* Currently the const item is always the first in the list of equal items */
inline Item* get_const() { return with_const ? equal_items.head() : NULL; }
void add_const(THD *thd, Item *c, Item *f = NULL);
void add_const(THD *thd, Item *c);
/** Add a non-constant item to the multiple equality */
void add(Item *f, MEM_ROOT *root) { equal_items.push_back(f, root); }
bool contains(Field *field);
@ -2110,7 +2104,8 @@ public:
Item *transform(THD *thd, Item_transformer transformer, uchar *arg);
virtual void print(String *str, enum_query_type query_type);
Item_result compare_type() const { return cmp.compare_type(); }
CHARSET_INFO *compare_collation() const;
CHARSET_INFO *compare_collation() const
{ return cmp.cmp_collation.collation; }
void set_context_field(Item_field *ctx_field) { context_field= ctx_field; }
void set_link_equal_fields(bool flag) { link_equal_fields= flag; }

2
sql/sql_select.cc
View File

@ -12699,7 +12699,7 @@ static bool check_simple_equality(THD *thd, const Item::Context &ctx,
already contains a constant and its value is not equal to
the value of const_item.
*/
item_equal->add_const(thd, const_item2, orig_field_item);
item_equal->add_const(thd, const_item2);
}
else
{