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.
Conversion from int and real numbers to UCS2 didn't work fine:
CONVERT(100, CHAR(50) UNICODE)
CONVERT(103.9, CHAR(50) UNICODE)
The problem appeared because numbers have binary charset, so,
simple charset recast binary->ucs2 was performed
instead of real conversion.
Fixed to make numbers pretend to be non-binary.
"Item_date_add_interval needs to have the int_type member as Public".
As explained in the bug report, this change is is to help http://search.cpan.org/~philips/DBIx-MyParse-0.20/
So please keep those members public.
Removed wrong fix for bug #14009 (use of abs() on null value causes problems with filesort)
Mark that add_time(), time_diff() and str_to_date() can return null values
length.
When temporary field created for DATE(LEFT(column,8)) expression, max_length
value is taken from Item_date_typecast, and it is getting it from underlaid
Item_func_left and it's max_length is 8 in given expression. And all this
results in stripping last 2 digits.
To Item_date_typecast class added its own fix_length_and_dec() function
that sets max_length value to 10, which is proper for DATE field.
does not work well together". Now using simplier and more correct
implementation of st_lex::unlink_first_table()/link_first_table_back()
(It also nicely handles case when global table list is created because
of implictly used time zone tables). (2nd attempt)
Fix for bug #7705 "CONVERT_TZ() crashes with subquery/WHERE on index
column". Implemented new approach for caching objects for constant
time zone arguments. Now instead of determining whenever these arguments
are constants and performing time zone lookup at fix_fields() stage, we
do it on first get_date() invocation.
Cleanup of global @@time_zone variable handling.
Instead of trying to open time zone tables during calculation of CONVERT_TZ() function
or setting of @@time_zone variable we should open and lock them with the rest of
statement's table (so we should add them to global table list) and after that use such
pre-opened tables for loading info about time zones.
Added basic per-thread time zone functionality (based on public
domain elsie-code). Now user can select current time zone
(from the list of time zones described in system tables).
All NOW-like functions honor this time zone, values of TIMESTAMP
type are interpreted as values in this time zone, so now
our TIMESTAMP type behaves similar to Oracle's TIMESTAMP WITH
LOCAL TIME ZONE (or proper PostgresSQL type).
WL#1266 "CONVERT_TZ() - basic time with time zone conversion
function".
Fixed problems described in Bug #2336 (Different number of warnings
when inserting bad datetime as string or as number). This required
reworking of datetime realted warning hadling (they now generated
at Field object level not in conversion functions).
Optimization: Now Field class descendants use table->in_use member
instead of current_thd macro.
Final version of patch.
Adds support for specifying of DEFAULT NOW() and/or ON UPDATE NOW()
clauses for TIMESTAMP field definition.
Current implementation allows only one such field per table and
uses several unireg types for storing info about this properties of
field. It should be replaced with better implementation when new
.frm format is introduced.
Cleaned up (and disabled part of) date/time/datetime format patch. One can't anymore change default read/write date/time/formats.
This is becasue the non standard datetime formats can't be compared as strings and MySQL does still a lot of datetime comparisons as strings
Changed flag argument to str_to_TIME() and get_date() from bool to uint
Removed THD from str_to_xxxx functions and Item class.
Fixed core dump when doing --print-defaults
Move some common string functions to strfunc.cc
Dates as strings are now of type my_charset_bin instead of default_charset()
Introduce IDENT_QUOTED to not have to create an extra copy of simple identifiers (all chars < 128)
Removed xxx_FORMAT_TYPE enums and replaced them with the old TIMESTAMP_xxx enums
Renamed some TIMESTAMP_xxx enums to more appropriate names
Use defines instead of integers for date/time/datetime string lengths
Added to build system and use the new my_strtoll10() function.
Item_extract needs special implementation for eq().
Item_func::eq doesn't work correctly because we have to compare
Item_extract::int_type parameters also
We need to propagate this to 4.1
like number-to-string-convertion-result, now
takes current database character set, instead of
thread character set. This makes it easy to be
SQL99 conformant and 4.0 compatible.
Item->thd_charset() is renamed to Item->default_charset()
as old name doesn't describe its nature anymore.
Changed timestamp to return string in YYYY-MM-DD HH:MM:SS format.
DATE_ADD() and related functions now returns correct DATE/DATETIME type depending on argument types.
Now all tests passes, still some work left to remove warnings in log files from mysql-test-run
Class for sending data from server to client (Protocol)
This handles both the old ( <= 4.0 ) protocol and then new binary protocol that is used for prepared statements.
Warning handling and initial prepared statement handling (last not complete yet)
Changed a lot of functions that returned 0/1 to my_bool type.
GRANT handling now uses read/write locks instead of mutex
Change basic net functions to use THD instead of NET
(needed for 4.1 protocol)
Use my_sprintf instead of sprintf() + strlen()
Added alloc_query() to be able to chare query initialization code with
prepared statements.
Cleanup handling of SHOW COUNT(*) WARNINGS and SELECT LAST_INSERT_ID()
Note that the following test fails (will be fixed ASAP):
sub_select, union, rpl_rotate_logs and rpl_mystery22
Some simple optimzations, more comments and indentation changes.
Add ` around database in 'use database' in binary log.
Moved max_error_count and max_warning_count to variables struct.
Removed SHOW_WARNS_COUNT and SHOW_ERRORS_COUNT calls.
Changed string functions to use character set of first string argument as default return characterset
(Each string function can change the above assumption if needed)
