equal constant under any circumstances.
In fact this substitution can be allowed if the field is
not of a type string or if the field reference serves as
an argument of a comparison predicate.
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.
too much memory. Instead, either create the equvalent SEL_TREE manually, or create only two ranges that
strictly include the area to scan
(Note: just to re-iterate: increasing NOT_IN_IGNORE_THRESHOLD will make optimization run slower for big
IN-lists, but the server will not run out of memory. O(N^2) memory use has been eliminated)
Multiple equalities were not adjusted after reading constant tables.
It resulted in neglecting good index based methods that could be
used to access of other tables.
- Added empty constructors and virtual destructors to many classes and structs
- Removed some usage of the offsetof() macro to instead use C++ class pointers
select result
Item equal objects are employed only at the optimize phase. Usually they are not
supposed to be evaluated. Yet in some cases we call the method val_int() for
them. Here we have to take care of restricting the predicate such an object
represents f1=f2= ...=fn to the projection of known fields fi1=...=fik.
Added a check for field's table being const in Item_equal::val_int().
If the field's table is not const val_int() just skips that field when
evaluating Item_equal.
cmp_item_sort_string::cmp() wasn't checking values_res variable for null.
Later called function was dereferenced it and crashed server.
Added null check to cmp_item_sort_string::cmp().
ESCAPE has length of 1 if specified and sql_mode is NO_BACKSLASH_ESCAPES
or has length of 0 or 1 in every other situation.
(approved patch applied on a up-to-date tree re-commit)
Fixed bugs #12101, #12102: wrong calculation of not_null_tables()
for some expressions.
The classes Item_func_between, Item_func_if, Item_func_in are modified.
Item_func_between/in objects can represent now [NOT]BETWEEN/IN expressions.
The class Item_func_opt_neg is added to factor out the functionality
common for the modified classes Item_func_between and Item_func_in.
item_cmpfunc.cc:
Fixed bugs #12101, #12102: wrong calculation of not_null_tables()
for some expressions.
Added Item_func_between::fix_fields(), Item_func_if::fix_fields(),
Item_func_in::fix_fields(). They correct generic calculation of
the not_null_tables attribute when it is needed.
Modified Item_func_between::val_int(), Item_func_in::val_int().
opt_range.cc:
Fixed bugs #12101, #12102: wrong calculation of not_null_tables()
for some expressions.
The function get_mm_tree() is modified. There cannot be NOT before
BETWEEN/IN anymore. Rather Item_func_between/in objects can represent
now [NOT]BETWEEN/IN expressions.
sql_yacc.yy:
Fixed bugs #12101, #12102: wrong calculation of not_null_tables()
for some expressions.
Item_func_between/in objects can represent now [NOT]BETWEEN/IN expresions.
join_outer.result:
Fixed some testcases results (bugs #12101, #12102)
join_outer.test:
Added testcases for bugs #12101, #12102
Bug 12611 : ESCAPE + LIKE do not work when the escape char is a multibyte one
Forgot to commit this file in the previous changeset,
together with other files.
view.
For Item_func_strcmp print() was not defined and for this class was called
print_op of it's parent class. Because of this strcmp() was printed wrongly
and this results int creation of broken view.
Added function Item_func_strcmp::print() which correctly prints strcmp()
function.
(IN() remove NULL rows only for tables from first argument (value which we looking for in IN() list) but not for tables from IN() list)
Also it will be better change Item::not_null_tables() to prohibit this optimisation by default for new created items in 5.0 or 5.1.
Fixed bug #9939: a wrong conversion of arguments
for functions COALESCE and IFNULL.
The str_op virtual method was added into Item_func_numhybrid.
item_func.cc:
Fixed bug #9939: a wrong conversion of arguments
for functions COALESCE and IFNULL.
The str_op virtual method was added into Item_func_numhybrid.
item_cmpfunc.h, item_cmpfunc.cc:
Fixed bug #9939: a wrong conversion of arguments
for functions COALESCE and IFNULL.
Item_func_coalesce and Item_func_ifnull now
inherit from a modified Item_func_numhybrid.
case.test, case.result:
Added test cases for bug #9939.
