"Process NATURAL and USING joins according to SQL:2003".
* Some of the main problems fixed by the patch:
- in "select *" queries the * expanded correctly according to
ANSI for arbitrary natural/using joins
- natural/using joins are correctly transformed into JOIN ... ON
for any number/nesting of the joins.
- column references are correctly resolved against natural joins
of any nesting and combined with arbitrary other joins.
* This patch also contains a fix for name resolution of items
inside the ON condition of JOIN ... ON - in this case items must
be resolved only against the JOIN operands. To support such
'local' name resolution, the patch introduces a stack of
name resolution contexts used at parse time.
NOTICE:
- This patch is not complete in the sense that
- there are 2 test cases that still do not pass -
one in join.test, one in select.test. Both are marked
with a comment "TODO: WL#2486".
- it does not include a new test specific for the task
Added a test case for bug #12392.
item_cmpfunc.cc:
Fixed bug #12392.
Missing handling of rows containing NULL components
when evaluating IN predicates caused a crash.
- Fixed some error condtion when handling dates with 'T'
- Added extra test for bug #11867 (Wrong result with "... WHERE ROW( a, b ) IN ( SELECT DISTINCT a, b WHERE ...)" to show it's not yet fixed
- Safety fixes and cleanups
Added test case for bug #11867.
Fixed results for two existing test cases.
subselect.test:
Added test case for bug #11867.
item_subselect.cc:
Fixed bug #11867.
Added missing code in Item_in_subselect::row_value_transformer
that caused problems for queries with
ROW(elems) IN (SELECT DISTINCT cols FROM ...).
Item_type_holder doesn't store information about length and exact type of
original item which results in redefining length to max_length and geometry
type to longtext.
Changed the way derived tables except unions are built. Now they are created
from original field list instead of list of Item_type_holder.
Fixed buf #11487.
Added a call of QUICK_RANGE_SELECT::init to the
QUICK_RANGE_SELECT::reset method. Without it the second
evaluation of a subquery employing the range access failed.
subselect.result, subselect.test:
Added a test case for bug #11487.
Added a test case for bug #9516.
item_subselect.h:
Fixed bug #9516.
The bug was due to that fact that the class Item_subselect
inherited the generic implementation of the function
not_null_tables that was not valid for the objects
of this class. As a result evaluation of the
not_null_tables attribute was not correct for subqueries.
This caused invalid transformations of outer joins into
inner joins.
Added a test case for bug #9338.
sql_select.cc:
Fixed bug #9338.
When an occurence of a field reference has to be replaced
by another field reference the whole Item_field must be
replaced.
item.cc:
Fixed bug #9338.
The method Item_field::replace_equal_field_processor was
replaced by Item_field::replace_equal_field. The new method
is used to replace the occurences of Item_field objects.
item.h:
Fixed bug #9338.
The virtual function replace_equal_field_processor was replaced
by replace_equal_field. The latter is supposed to be used as a
callback function in calls of the method transform.
CAST() now produces warnings when casting a wrong INTEGER or CHAR values. This also applies to implicite string to number casts. (Bug #5912)
ALTER TABLE now fails in STRICT mode if it generates warnings.
Inserting a zero date in a DATE, DATETIME or TIMESTAMP column during TRADITIONAL mode now produces an error. (Bug #5933)
Remove TMP_TABLE_PARAM::copy_funcs_it. TMP_TABLE_PARAM is a member of JOIN which is
copied via memcpy, and List_iterator_fast TMP_TABLE_PARAM::copy_funcs_it ends up
pointing to the wrong List.
Added test cases for bug #7351.
item_cmpfunc.cc:
Fixed bug #7351: incorrect result for a query with a
subquery returning empty set.
If in the predicate v IN (SELECT a FROM t WHERE cond)
v is null, then the result of the predicate is either
INKNOWN or FALSE. It is FALSE if the subquery returns
an empty set.
item_subselect.cc:
Fixed bug #7351: incorrect result for a query with a
subquery returning empty set.
The problem was due to not a quite legal transformation
for 'IN' subqueries. A subquery containing a predicate
of the form
v IN (SELECT a FROM t WHERE cond)
was transformed into
EXISTS(SELECT a FROM t WHERE cond AND (a=v OR a IS NULL)).
Yet, this transformation is valid only if v is not null.
If v is null, then, in the case when
(SELECT a FROM t WHERE cond) returns an empty set the value
of the predicate is FALSE, otherwise the result of the
predicate is INKNOWN.
The fix resolves this problem by changing the result
of the transformation to
EXISTS(SELECT a FROM t WHERE cond AND (v IS NULL OR (a=v OR a IS NULL)))
in the case when v is nullable.
The new transformation prevents applying the lookup
optimization for IN subqueries. To make it still
applicable we have to introduce guarded access methods.
