Fixed compiler warnings (detected by VC++):
- Removed not used variables
- Added casts
- Fixed wrong assignments to bool
- Fixed wrong calls with bool arguments
- Added missing argument to store(longlong), which caused wrong store method to be called.
When implicitly converting string fields to numbers the
string-to-number conversion error was not sent to the client.
Added code to send the conversion error as warning.
We also need to prevent generation of warnings from the places
where val_xxx() methods are called for the sole purpose of updating
the Item::null_value flag.
To achieve that a special function is added (and called) :
update_null_value(). This function will set the no_errors flag and
will call val_xxx(). The warning generation in Field_string::val_xxx()
will use the flag when generating the conversion warnings.
specifying DEFAULT
This was not specific to datetime. When there is no default value
for a column, and the user inserted DEFAULT, we would write
uninitialized memory to the table.
Now, insist on writing a default value, a zero-ish value, the same
one that comes from inserting NULL into a not-NULL field.
(This is, at best, really strange behavior that comes from allowing
sloppy usage, and serves as a good reason always to run one's server
in a strict SQL mode.)
When compiling GROUP BY Item_ref instances are dereferenced in
setup_copy_fields(), i.e. replaced with the corresponding Item_field
(if they point to one) or Item_copy_string for the other cases.
Since the Item_ref (in the Item_field case) is no longer used the information
about the aliases stored in it is lost.
Fixed by preserving the column, table and DB alias on dereferencing Item_ref
The problem was that any VIEW columns had always implicit derivation.
Fix: derivation is now copied from the original expression
given in VIEW definition.
For example:
- a VIEW column which comes from a string constant
in CREATE VIEW definition have now coercible derivation.
- a VIEW column having COLLATE clause
in CREATE VIEW definition have now explicit derivation.
The parser is allocating Item_field for references by name in ORDER BY
expressions. Such expressions however may point not only to Item_field
in the select list (or to a table column) but also to an arbitrary Item.
This causes Item_field::fix_fields to throw an error about missing
column.
The fix substitutes Item_field for the reference with an Item_ref when
not pointing to Item_field.
select OK.
The SQL parser was using Item::name to transfer user defined function attributes
to the user defined function (udf). It was not distinguishing between user defined
function call arguments and stored procedure call arguments. Setting Item::name
was causing Item_ref::print() method to print the argument as quoted identifiers
and caused views that reference aggregate functions as udf call arguments (and
rely on Item::print() for the text of the view to store) to throw an undefined
identifier error.
Overloaded Item_ref::print to print aggregate functions as such when printing
the references to aggregate functions taken out of context by split_sum_func2()
Fixed the parser to properly detect using AS clause in stored procedure arguments
as an error.
Fixed printing the arguments of udf call to print properly the udf attribute.
Re-execution of a parametrized prepared statement or a stored routine
with a SELECT that use LEFT JOIN with second table having only one row
could yield incorrect result.
The problem appeared only for left joins with second table having only
one row (aka const table) and equation conditions in ON or WHERE clauses
that depend on the argument passed. Once the condition was false for
second const table, a NULL row was created for it, and any field involved
got NULL-value flag, which then was never reset.
The cause of the problem was that Item_field::null_value could be set
without being reset for re-execution. The solution is to reset
Item_field::null_value in Item_field::cleanup().
an ALL/ANY quantified subquery in HAVING.
The Item::split_sum_func2 method should not create Item_ref
for objects of any class derived from Item_subselect.
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.
A date can be represented as an int (like 20060101) and as a string (like
"2006.01.01"). When a DATE/TIME field is compared in one SELECT against both
representations the constant propagation mechanism leads to comparison
of DATE as a string and DATE as an int. In this example it compares 2006 and
20060101 integers. Obviously it fails comparison although they represents the
same date.
Now the Item_bool_func2::fix_length_and_dec() function sets the comparison
context for items being compared. I.e. if items compared as strings the
comparison context is STRING.
The constant propagation mechanism now doesn't mix items used in different
comparison contexts. The context check is done in the
Item_field::equal_fields_propagator() and in the change_cond_ref_to_const()
functions.
Also the better fix for bug 21159 is introduced.
The Item::tmp_table_field_from_field_type() function creates Field_datetime
object instead of Field_timestamp object for timestamp field thus always
changing data type is a tmp table is used.
The Field_blob object constructor which is used in the
Item::tmp_table_field_from_field_type() is always setting packlength field of
newly created blob to 4. This leads to changing fields data type for example
from the blob to the longblob if a temporary table is used.
The Item::make_string_field() function always converts Field_string objects
to Field_varstring objects. This leads to changing data type from the
char/binary to varchar/varbinary.
Added appropriate Field_timestamp object constructor for using in the
Item::tmp_table_field_from_field_type() function.
Added Field_blob object constructor which sets pack length according to
max_length argument.
The Item::tmp_table_field_from_field_type() function now creates
Field_timestamp object for a timestamp field.
The Item_type_holder::display_length() now returns correct NULL length NULL
length.
The Item::make_string_field() function now doesn't change Field_string to
Field_varstring in the case of Item_type_holder.
The Item::tmp_table_field_from_field_type() function now uses the Field_blob
constructor which sets packlength according to max_length.
This was only demonstrated by the use of PASSWORD(), it was not related to
that function at all. The calculation of the size of a field in the results
of a UNION did not take into account the possible growth of a string field
when being converted to the aggregated character set.
and Stored Procedure
The essence of the bug was that for every re-execution of stored
routine or prepared statement new items for character set conversions
were created, thus increasing the number of items and the time of their
processing, and creating memory leak.
No test case is provided since current test suite can't cover such type
of bugs.
When an alias is set to a column leading spaces are removed from the alias.
But when this is done on aliases set by user this can lead to confusion.
Now Item::set_name() method issues the warning if leading spaces were removed
from an alias set by user.
New warning message is added.
NDB table".
SQL-layer was not marking fields which were used in triggers as such. As
result these fields were not always properly retrieved/stored by handler
layer. So one might got wrong values or lost changes in triggers for NDB,
Federated and possibly InnoDB tables.
This fix solves the problem by marking fields used in triggers
appropriately.
Also this patch contains the following cleanup of ha_ndbcluster code:
We no longer rely on reading LEX::sql_command value in handler in order
to determine if we can enable optimization which allows us to handle REPLACE
statement in more efficient way by doing replaces directly in write_row()
method without reporting error to SQL-layer.
Instead we rely on SQL-layer informing us whether this optimization
applicable by calling handler::extra() method with
HA_EXTRA_WRITE_CAN_REPLACE flag.
As result we no longer apply this optimzation in cases when it should not
be used (e.g. if we have on delete triggers on table) and use in some
additional cases when it is applicable (e.g. for LOAD DATA REPLACE).
Finally this patch includes fix for bug#20728 "REPLACE does not work
correctly for NDB table with PK and unique index".
This was yet another problem which was caused by improper field mark-up.
During row replacement fields which weren't explicity used in REPLACE
statement were not marked as fields to be saved (updated) so they have
retained values from old row version. The fix is to mark all table
fields as set for REPLACE statement. Note that in 5.1 we already solve
this problem by notifying handler that it should save values from all
fields only in case when real replacement happens.
In some functions dealing with strings and character sets, the wrong
pointers were saved for restoration in THD::rollback_item_tree_changes().
This could potentially cause random corruption or crashes.
Fixed by passing the original Item ** locations, not local stack copies.
Also remove unnecessary use of default arguments.
After view onening real view db name and table name are placed
into table_list->view_db & table_list->view_name.
Item_field class does not handle these names properly during
intialization of Send_field.
The fix is to use new class 'Item_ident_for_show'
which sets correct view db name and table name for Send_field.
The convert_constant_item() function converts constant items to ints on
prepare phase to optimize execution speed. In this case it tries to evaluate
subselect which contains a derived table and is contained in a derived table.
All derived tables are filled only after all derived tables are prepared.
So evaluation of subselect with derived table at the prepare phase will
return a wrong result.
A new flag with_subselect is added to the Item class. It indicates that
expression which this item represents is a subselect or contains a subselect.
It is set to 0 by default. It is set to 1 in the Item_subselect constructor
for subselects.
For Item_func and Item_cond derived classes it is set after fixing any argument
in Item_func::fix_fields() and Item_cond::fix_fields accordingly.
The convert_constant_item() function now doesn't convert a constant item
if the with_subselect flag set in it.
The select statement that specified a view could be
slightly changed when the view was saved in a frm file.
In particular references to an alias name in the HAVING
clause could be substituted for the expression named by
this alias.
This could result in an error message for a query of
the form SELECT * FROM <view>. Yet no such message
appeared when executing the query specifying the view.
