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MDEV-8707 Wrong result for

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SELECT..WHERE varchar_column=DATE'2001-01-01' AND varchar_column='2001-01-01'
This commit is contained in:
Alexander Barkov
2015-08-31 18:18:10 +04:00
parent 44a99777bf
commit a3c24ee739
9 changed files with 208 additions and 27 deletions
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53
sql/sql_select.cc
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@@ -12513,7 +12513,6 @@ finish:
*/
static bool check_simple_equality(THD *thd, Item *left_item, Item *right_item,
const Item_bool_func *item,
COND_EQUAL *cond_equal)
{
Item *orig_left_item= left_item;
@@ -12639,27 +12638,35 @@ static bool check_simple_equality(THD *thd, Item *left_item, Item *right_item,
}
if (const_item &&
field_item->result_type() == const_item->result_type())
field_item->field->test_if_equality_guarantees_uniqueness(const_item))
{
bool copyfl;
/*
field_item and const_item are arguments of a scalar or a row
comparison function:
WHERE column=constant
WHERE (column, ...) = (constant, ...)
if (field_item->cmp_type() == STRING_RESULT)
{
CHARSET_INFO *cs= field_item->field->charset();
if (!item)
{
Item_func_eq *eq_item;
if (!(eq_item= new (thd->mem_root) Item_func_eq(thd, orig_left_item,
orig_right_item)) ||
eq_item->set_cmp_func_and_arg_cmp_context())
return FALSE;
eq_item->quick_fix_field();
item= eq_item;
}
if ((cs != item->compare_collation()) ||
!cs->coll->propagate(cs, 0, 0))
return FALSE;
}
The owner comparison function has previously called fix_fields(),
so field_item and const_item should be directly comparable items,
field_item->cmp_context and const_item->cmp_context should be set.
In case of string comparison, charsets and collations of
field_item and const_item should have already be aggregated
for comparison, all necessary character set converters installed
and fixed.
In case of string comparison, const_item can be either:
- a weaker constant that does not need to be converted to field_item:
WHERE latin1_field = 'latin1_const'
WHERE varbinary_field = 'latin1_const'
WHERE latin1_bin_field = 'latin1_general_ci_const'
- a stronger constant that does not need to be converted to field_item:
WHERE latin1_field = binary 0xDF
WHERE latin1_field = 'a' COLLATE latin1_bin
- a result of conversion (e.g. from the session character set)
to the character set of field_item:
WHERE latin1_field = 'utf8_string_with_latin1_repertoire'
*/
bool copyfl;
Item_equal *item_equal = find_item_equal(cond_equal,
field_item->field, &copyfl);
@@ -12737,7 +12744,7 @@ static bool check_row_equality(THD *thd, Item *left_row, Item_row *right_row,
}
else
{
is_converted= check_simple_equality(thd, left_item, right_item, 0,
is_converted= check_simple_equality(thd, left_item, right_item,
cond_equal);
}
@@ -12799,7 +12806,7 @@ bool Item_func_eq::check_equality(THD *thd, COND_EQUAL *cond_equal,
(Item_row *) right_item,
cond_equal, eq_list);
}
return check_simple_equality(thd, left_item, right_item, this, cond_equal);
return check_simple_equality(thd, left_item, right_item, cond_equal);
}
@@ -15457,6 +15464,8 @@ Item_func_isnull::remove_eq_conds(THD *thd, Item::cond_result *cond_value,
/*
psergey-todo: this returns false for int_column='1234' (here '1234' is a
constant. Need to discuss this with Bar).
See also Field::test_if_equality_guaranees_uniqueness(const Item *item);
*/
static bool
test_if_equality_guarantees_uniqueness(Item *l, Item *r)