From 47311e8e878a0f049c3f3b2a1c1dea454800d70a Mon Sep 17 00:00:00 2001 From: unknown Date: Tue, 13 Jun 2006 19:09:24 +0400 Subject: Fixed bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. All date/time functions has the STRING result type thus their results are compared as strings. The string date representation allows a user to skip some of leading zeros. This can lead to wrong comparison result if a date/time function result is compared to such a string constant. The idea behind this bug fix is to compare results of date/time functions and data/time constants as ints, because that date/time representation is more exact. To achieve this the agg_cmp_type() is changed to take in the account that a date/time field or an date/time item should be compared as ints. This bug fix is partially back ported from 5.0. The agg_cmp_type() function now accepts THD as one of parameters. In addition, it now checks if a date/time field/function is present in the list. If so, it tries to coerce all constants to INT to make date/time comparison return correct result. The field for the constant coercion is taken from the Item_field or constructed from the Item_func. In latter case the constructed field will be freed after conversion of all constant items. Otherwise the result is same as before - aggregated with help of the item_cmp_type() function. From the Item_func_between::fix_length_and_dec() function removed the part which was converting date/time constants to int if possible. Now this is done by the agg_cmp_type() function. The new function result_as_longlong() is added to the Item class. It indicates that the item is a date/time item and result of it can be compared as int. Such items are date/time fields/functions. Correct val_int() methods are implemented for classes Item_date_typecast, Item_func_makedate, Item_time_typecast, Item_datetime_typecast. All these classes are derived from Item_str_func and Item_str_func::val_int() converts its string value to int without regard to the date/time type of these items. Arg_comparator::set_compare_func() and Arg_comparator::set_cmp_func() functions are changed to substitute result type of an item with the INT_RESULT if the item is a date/time item and another item is a constant. This is done to get a correct result of comparisons like date_time_function() = string_constant. mysql-test/r/cast.result: Fixed wrong test case result after bug fix#16377. sql/item_timefunc.h: Fixed bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. The result_as_longlong() function is set to return TRUE for these classes: Item_date, Item_date_func, Item_func_curtime, Item_func_sec_to_time, Item_date_typecast, Item_time_typecast, Item_datetime_typecast, Item_func_makedate. sql/item_timefunc.cc: Fixed bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result.Correct val_int() methods are implemented for classes Item_date_typecast, Item_func_makedate, Item_time_typecast, Item_datetime_typecast. sql/item_cmpfunc.h: Fixed bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. Arg_comparator::set_compare_func() and Arg_comparator::set_cmp_func() functions are changed to substitute result type of an item with the INT_RESULT if the item is a date/time item and another item is a constant. sql/field.cc: Fixed bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. Field::set_warning(), Field::set_datetime_warning() now use current_thd to get thd if table isn't set. sql/item_cmpfunc.cc: Fixed bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. The agg_cmp_type() function now accepts THD as one of parameters. In addition, it now checks if a date/time field/function is present in the list. If so, it tries to coerce all constants to INT to make date/time comparison return correct result. The field for the constant coercion is taken from the Item_field or constructed from the Item_func. In latter case the constructed field will be freed after conversion of all constant items. Otherwise the result is same as before - aggregated with help of the item_cmp_type() function. sql/item.h: The new function result_as_longlong() is added to the Item class. It indicates that the item is a date/time item and result of it can be compared as int. Such items are date/time fields/functions. mysql-test/t/func_time.test: Added test case fot bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. mysql-test/r/func_time.result: Added test case fot bug#16377: result of DATE/TIME functions were compared as strings which can lead to a wrong result. --- sql/item.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'sql/item.h') diff --git a/sql/item.h b/sql/item.h index 66da7ad4e74..eca8ee184a1 100644 --- a/sql/item.h +++ b/sql/item.h @@ -327,6 +327,14 @@ public: cleanup(); delete this; } + /* + result_as_longlong() must return TRUE for Items representing DATE/TIME + functions and DATE/TIME table fields. + Those Items have result_type()==STRING_RESULT (and not INT_RESULT), but + their values should be compared as integers (because the integer + representation is more precise than the string one). + */ + virtual bool result_as_longlong() { return FALSE; } }; @@ -450,6 +458,10 @@ public: Item *get_tmp_table_item(THD *thd); void cleanup(); inline uint32 max_disp_length() { return field->max_length(); } + bool result_as_longlong() + { + return field->can_be_compared_as_longlong(); + } friend class Item_default_value; friend class Item_insert_value; friend class st_select_lex_unit; @@ -973,6 +985,10 @@ public: } Item *real_item() { return *ref; } void print(String *str); + bool result_as_longlong() + { + return (*ref)->result_as_longlong(); + } }; -- cgit v1.2.1