Post fix for bug#23800.
The Item_field constructor now increases the select_n_where_fields counter.
sql_yacc.yy:
Post fix for bug#23800.
Take into account fields that might be added by subselects.
sql_lex.h:
Post fix for bug#23800.
Added the select_n_where_fields variable to the st_select_lex class.
sql_lex.cc:
Post fix for bug#23800.
Initialization of the select_n_where_fields variable.
it doesn't select.
This bug was fixed along with bug #16861: User defined variable can
have a wrong value if a tmp table was used.
There the fix consisted of Item_func_set_user_var overloading the method
Item::save_in_field. Consider the query from the test case:
INSERT INTO foo( bar, baz )
SELECT
bar,
@newBaz := 1 + baz
FROM
foo
WHERE
quux <= 0.1;
Here the assignment expression '@newBaz := 1 + baz' is represented by an
Item_func_set_user_var. Its member method save_in_field, which writes the
value of this assignment into the result field, writes the val_xxx() value,
which is not updated at this point. In the fix introduced by the patch,
the save_in_field method reads the actual variable value instead.
See also comment for
ChangeSet@1.2368.1.3, 2007-01-09 23:24:56+03:00, evgen@moonbone.local +4 -0
and comment for
Item_func_set_user_var::save_in_field (item_func.cc)
created for sorting.
Any outer reference in a subquery was represented by an Item_field object.
If the outer select employs a temporary table all such fields should be
replaced with fields from that temporary table in order to point to the
actual data. This replacement wasn't done and that resulted in a wrong
subquery evaluation and a wrong result of the whole query.
Now any outer field is represented by two objects - Item_field placed in the
outer select and Item_outer_ref in the subquery. Item_field object is
processed as a normal field and the reference to it is saved in the
ref_pointer_array. Thus the Item_outer_ref is always references the correct
field. The original field is substituted for a reference in the
Item_field::fix_outer_field() function.
New function called fix_inner_refs() is added to fix fields referenced from
inner selects and to fix references (Item_ref objects) to these fields.
The new Item_outer_ref class is a descendant of the Item_direct_ref class.
It additionally stores a reference to the original field and designed to
behave more like a field.
Several problems fixed:
1. There was a "catch-all" context initialization in setup_tables()
that was causing the table that we insert into to be visible in the
SELECT part of an INSERT .. SELECT .. statement with no tables in
its FROM clause. This was making sure all the under-initialized
contexts in various parts of the code are not left uninitialized.
Fixed by removing the "catch-all" statement and initializing the
context in the parser.
2. Incomplete name resolution context when resolving the right-hand
values in the ON DUPLICATE KEY UPDATE ... part of an INSERT ... SELECT ...
caused columns from NATURAL JOIN/JOIN USING table references in the
FROM clause of the select to be unavailable.
Fixed by establishing a proper name resolution context.
3. When setting up the special name resolution context for problem 2
there was no check for cases where an aggregate function without a
GROUP BY effectively takes the column from the SELECT part of an
INSERT ... SELECT unavailable for ON DUPLICATE KEY UPDATE.
Fixed by checking for that condition when setting up the name
resolution context.
