It's a generic function, not using anything from Arg_comparator.
Make it a static function, not a class method, to be able to use
it later without Arg_comparator
reorder items in args[] array. Instead of
when1,then1,when2,then2,...[,case][,else]
sort them as
[case,]when1,when2,...,then1,then2,...[,else]
in this case all items used for comparison take a continuous part
of the array and can be aggregated directly. and all items that
can be returned take a continuous part of the array and can be
aggregated directly. Old code had to copy them to a temporary
array before aggreation, and then copy back (thd->change_item_tree)
everything that was changed.
The problem was that Item_func_hybrid_field_type::get_date() did not
convert the result to the correct data type, so MYSQL_TIME::time_type
of the get_date() result could be not in sync with field_type().
Changes:
1. Adding two new classes Datetime and Date to store MYSQL_TIMESTAMP_DATETIME
and MYSQL_TIMESTAMP_DATE values respectively
(in addition to earlier added class Time, for MYSQL_TIMESTAMP_TIME values).
2. Adding Item_func_hybrid_field_type::time_op().
It performs the operation using TIME representation,
and always returns a MYSQL_TIME value with time_type=MYSQL_TIMESTAMP_TIME.
Implementing time_op() for all affected children classes.
3. Fixing all implementations of date_op() to perform the operation
using strictly DATETIME representation. Now they always return a MYSQL_TIME
value with time_type=MYSQL_TIMESTAMP_{DATE|DATETIME},
according to the result data type.
4. Removing assignment of ltime.time_type to mysql_timestamp_type()
from all val_xxx_from_date_op(), because now date_op() makes sure
to return a proper MYSQL_TIME value with a good time_type (and other member)
5. Adding Item_func_hybrid_field_type::val_xxx_from_time_op().
6. Overriding Type_handler_time_common::Item_func_hybrid_field_type_val_xxx()
to call val_xxx_from_time_op() instead of val_xxx_from_date_op().
7. Modified Item_func::get_arg0_date() to return strictly a TIME value
if TIME_TIME_ONLY is passed, or return strictly a DATETIME value otherwise.
If args[0] returned a value of a different temporal type,
(for example a TIME value when TIME_TIME_ONLY was not passed,
or a DATETIME value when TIME_TIME_ONLY was passed), the conversion
is automatically applied.
Earlier, get_arg0_date() did not guarantee a result in
accordance to TIME_TIME_ONLY flag.
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
MDEV-14957: JOIN::prepare gets unusable "conds" as argument
Do not touch merged derived (it is irreversible)
Fix first argument of in_optimizer for calls possible before fix_fields()
Merge branch '10.3' into trunk
Both field_visibility and VERS_HIDDEN_FLAG exist independently.
TODO:
VERS_HIDDEN_FLAG should be replaced with SYSTEM_INVISIBLE (or COMPLETELY_INVISIBLE?).
TODO:
- Make get_thd_memroot() inline
- To do this, we need to reduce dependence of include files, especially
so that sql_class.h is not depending in item.h
Make differentiation between pullout for merge and pulout of outer field during exists2in transformation.
In last case the field was outer and so we can safely start from name resolution context of the SELECT where it was pulled.
Old behavior lead to inconsistence between list of tables and outer name resolution context (which skips one SELECT for merge purposes) which creates problem vor name resolution.
As a result of this merge the code for the following tasks appears in 10.3:
- MDEV-12172 Implement tables specified by table value constructors
- MDEV-12176 Transform [NOT] IN predicate with long list of values INTO
[NOT] IN subquery.
Side effect: the second debug Note in cache_temporal_4265.result disappeared.
Before this change:
- During JOIN::cache_const_exprs(),
Item::get_cache() for Item_date_add_interval() was called.
The data type for date_add('2001-01-01',interval 5 day) is VARCHAR,
because the first argument is VARCHAR (not temporal).
Item_get_cache() created Item_cache_str('2001-01-06').
- During evaluate_join_record(), get_datetime_value() was called,
which called Item::get_date() for Item_cache_str('2001-01-06').
This gave the second Note. Then, get_datetime_value() created
a new cache, now Item_cache_temporal for '2001-01-06', so not
further str_to_datetime() happened.
After this change:
- During tem_bool_rowready_func2::fix_length_and_dec(),
Arg_comparator::set_cmp_func_datetime() is called,
which immediately creates an instance of Item_cache_date for
the result of date_add('2001-01-01',interval 5 day).
So later no str_to_datetime happens any more,
neither during JOIN::cache_const_exprs(),
nor during evaluate_join_record().
Fixing the data type for the "fuzzydate" parameter to
Item_func_hybrid_field_type::date_op() from uint to ulonglong,
for consistency with Item::get_date().
