subqueries on information schema that use MIN/MAX aggregation.
Execution of some correlated subqueries may set the value
of null_row to 1 for tables used in the subquery.
If the the subquery is on information schema it causes
rejection of any row for the following executions of
the subquery in the case when an optimization filtering
by some condition is applied.
The fix restores the value of the null_row flag for
each execution of a subquery on information schema.
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.
When making a place to store field values at the start of each group
the real item (not the reference) must be used when deciding which column
to copy.
An aggregate function reference was resolved incorrectly and
caused a crash in count_field_types.
Must use real_item() to get to the real Item instance through
the reference
The problem was that store_top_level_join_columns() incorrectly assumed
that the left/right neighbor of a nested join table reference can be only
at the same level in the join tree.
The fix checks if the current nested join table reference has no immediate
left/right neighbor, and if so chooses the left/right neighbors of the
nearest upper level, where these references are != NULL.
for class Item_func_trim.
For 4.1 it caused wrong output for EXPLAIN EXTENDED commands
if expressions with the TRIM function of two arguments were used.
For 5.0 it caused an error message when trying to select
from a view with the TRIM function of two arguments.
This unexpected error message was due to the fact that the
print method for the class Item_func_trim was inherited from
the class Item_func. Yet the TRIM function does not take a list
of its arguments. Rather it takes the arguments in the form:
[{BOTH | LEADING | TRAILING} [remstr] FROM] str) |
[remstr FROM] str
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.
The bug caused a crash of the server if a subquery with
ORDER BY DESC used the range access method.
The bug happened because the method QUICK_SELECT_DESC::reset
was not reworked after MRR interface had been introduced.
The bug was due to a loss happened during a refactoring made
on May 30 2005 that modified the function JOIN::reinit.
As a result of it for any subquery the value of offset_limit_cnt
was not restored for the following executions. Yet the first
execution of the subquery made it equal to 0.
The fix restores this value in the function JOIN::reinit.
DESCRIBE returned the type BIGINT for a column of a view if the column
was specified by an expression over values of the type INT.
E.g. for the view defined as follows:
CREATE VIEW v1 SELECT COALESCE(f1,f2) FROM t1
DESCRIBE returned type BIGINT for the only column of the view if f1,f2 are
columns of the INT type.
At the same time DESCRIBE returned type INT for the only column of the table
defined by the statement:
CREATE TABLE t2 SELECT COALESCE(f1,f2) FROM t1.
This inconsistency was removed by the patch.
Now the code chooses between INT/BIGINT depending on the
precision of the aggregated column type.
Thus both DESCRIBE commands above returns type INT for v1 and t2.
* don't use join cache when the incoming data set is already ordered
for ORDER BY
This choice must be made because join cache will effectively
reverse the join order and the results will be sorted by the index
of the table that uses join cache.
may return a wrong result.
An Item_sum_hybrid object has the was_values flag which indicates whether any
values were added to the sum function. By default it is set to true and reset
to false on any no_rows_in_result() call. This method is called only in
return_zero_rows() function. An ALL/ANY subquery can be optimized by MIN/MAX
optimization. The was_values flag is used to indicate whether the subquery
has returned at least one row. This bug occurs because return_zero_rows() is
called only when we know that the select will return zero rows before
starting any scans but often such information is not known.
In the reported case the return_zero_rows() function is not called and
the was_values flag is not reset to false and yet the subquery return no rows
Item_func_not_all and Item_func_nop_all functions return a wrong
comparison result.
The end_send_group() function now calls no_rows_in_result() for each item
in the fields_list if there is no rows were found for the (sub)query.
The problem is that the author used the wrong function to send a warning to the
user about truncation of data. push_warning() takes a constant string and
push_warning_printf() takes a format and variable arguments to fill it.
Since the string we were complaining about contains percent characters, the
printf() code interprets the "%Y" et c. that the user sends. That's wrong, and
often causes a crash, especially if the date mentions seconds, "%s".
A alternate fix would be to use push_warning_printf(..., "%s", warn_buff) .
