"update existingtable set anycolumn=nonexisting order by nonexisting" would crash
the server.
Though we would find the reference to a field, that doesn't mean we can then use
it to set some values. It could be a reference to another field. If it is NULL,
don't try to use it to set values in the Item_field and instead return an error.
Over the previous patch, this signals an error at the location of the error, rather
than letting the subsequent deref signal it.
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.
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.
In the code that converts IN predicates to EXISTS predicates it is changing
the select list elements to constant 1. Example :
SELECT ... FROM ... WHERE a IN (SELECT c FROM ...)
is transformed to :
SELECT ... FROM ... WHERE EXISTS (SELECT 1 FROM ... HAVING a = c)
However there can be no FROM clause in the IN subquery and it may not be
a simple select : SELECT ... FROM ... WHERE a IN (SELECT f(..) AS
c UNION SELECT ...) This query is transformed to : SELECT ... FROM ...
WHERE EXISTS (SELECT 1 FROM (SELECT f(..) AS c UNION SELECT ...)
x HAVING a = c) In the above query c in the HAVING clause is made to be
an Item_null_helper (a subclass of Item_ref) pointing to the real
Item_field (which is not referenced anywhere else in the query anymore).
This is done because Item_ref_null_helper collects information whether
there are NULL values in the result. This is OK for directly executed
statements, because the Item_field pointed by the Item_null_helper is
already fixed when the transformation is done. But when executed as
a prepared statement all the Item instances are "un-fixed" before the
recompilation of the prepared statement. So when the Item_null_helper
gets fixed it discovers that the Item_field it points to is not fixed
and issues an error. The remedy is to keep the original select list
references when there are no tables in the FROM clause. So the above
becomes : SELECT ... FROM ... WHERE EXISTS (SELECT c FROM (SELECT f(..)
AS c UNION SELECT ...) x HAVING a = c) In this way c is referenced
directly in the select list as well as by reference in the HAVING
clause. So it gets correctly fixed even with prepared statements. And
since the Item_null_helper subclass of Item_ref_null_helper is not used
anywhere else it's taken out.
union.result, union.test:
Adding test case.
item.cc:
Allow safe character set conversion in UNION
- string constant to column's charset
- to unicode
Thus, UNION now works the same with CONCAT (and other string functions)
in respect of aggregating arguments with different character sets.
crash
resolve_const_item() substitutes item which will evaluate to constant with
equvalent constant item, basing on the item's result type. In this case
subselect was resolved as constant, and resolve_const_item() was substituting
it's result's Item_caches to Item_null. Later Item_cache's function was called
for Item_null object, which caused server crash.
resolve_const_item() now substitutes constants for items with
result_type == ROW_RESULT only for Item_rows.
item_strfunc.h, item_strfunc.cc, item.cc:
Try to convert a const item into destination
character set. If conversion happens without
data loss, then cache the converted value
and return it during val_str().
Otherwise, if conversion loses data, return
Illeral mix of collations error, as it happened
previously.
ctype_recoding.result, ctype_recoding.test:
Fixing tests accordingly.
VALUES() can only refer to table insert going to.
But Item_insert_value::fix_fields() were passing to it's arg full table list,
This results in finding second column which shouldn't be found, and
failing with error about ambiguous field.
Item_insert_value::fix_fields() now passes only first table of full table
list.
When fixing Item_func_plus in ORDER BY clause field c is searched in all
opened tables, but because c is an alias it wasn't found there.
This patch adds a flag to select_lex which allows Item_field::fix_fields()
to look up in select's item_list to find aliased fields.
resolve_const_item() assumed to be not called for Item_row items. For
ensuring that DBUG_ASSERT(0) was set there.
This patch adds section for Item_row items. If it can it recursively calls
resolve_const_item() for each item the Item_row contains. If any of the
contained items is null then whole Item_row substitued by Item_null. Otherwise
it just returns.
This fix is cancellation of ChangeSet
1.2329 05/07/12 08:35:30 reggie@linux.site +8 -0
Bug 7142 Show Fields from fails using Borland's dbExpress interface
The reason is we can't fix bug#7142 without
breaking of existing applications/APIs that worked fine with earlier 4.1
bug 7142 is fixed in 5.0
Item::tmp_table_field_from_field_type() and create_tmp_field_from_item()
was converting string field to blob depending on byte-wise length instead of
character length, which results in converting valid varchar string with
length == 86 to longtext.
Made that functions above take into account max width of character when
converting string fields to blobs.
In cp932, '\' character can be the second byte in a
multi-byte character stream. This makes it difficult to use
mysql_escape_string. Added flag to indicate which languages allow
'\' as second byte of multibyte sequence so that when putting a prepared
statement into the binlog we can decide at runtime whether hex encoding
is really needed.
item.cc:
item.h:
Adding Item_param::safe_charset_converter,
not to return collation mix error if
parameter can be converted into operation
character set.
ctype_utf8.result:
adding test case
ctype_utf8.test:
adding test case
fixing tests accordingly
item.cc:
Bug #10892 user variables not auto cast for comparisons
When mixing strings with different character sets,
and coercibility is the same, we allow conversion
if one character set is superset for other character set.
Adding test
item_sum.cc:
Adding a call for collation/charset aggregation,
to collect attributes from the arguments. The actual bug fix.
item_func.h, item_func.cc, item.h, item.cc:
- Removing collation aggrgation functions from Item_func class
in item.cc, and adding it as non-class functions in item.cc
to be able to reuse this code for group_concat.
- Adding replacement for these functions into Item_func class
as wrappers for moved functions, to minizize patch size,
data": remove the fix for another bug (8807) that
added OUTER_REF_TABLE_BIT to all subqueries that used a placeholder
to prevent their evaluation at prepare. As this bit hanged in
Item_subselect::used_tables_cache for ever, a constant subquery with
a placeholder was never evaluated as such, which caused wrong
choice of the execution plan for the statement.
- to fix Bug#8807 backport a better fix from 5.0
- post-review fixes.
adding test case
sql_table.cc:
sql_table.cc:
- do not create a new item when charsets are the same
- return ER_INVALID_DEFAULT if default value cannot
be converted into the column character set.
item.cc:
- Allow conversion not only to Unicode,
but also to and from "binary".
- Adding safe_charset_converter() for Item_num
and Item_varbinary, returning a fixed const Item.
The problem here is that columns that have an especially long type
such as an enum type with many options would be longer than 40 chars
but the type column returned from show columns always was defined
as varchar(40).
This is fixed in 5.0 using info schema.
#9728 'Decreased functionality in "on duplicate key update
#8147 'a column proclaimed ambigous in INSERT ... SELECT .. ON DUPLICATE'
This ensures fields are uniquely qualified and also that one can't update other tables in the ON DUPLICATE KEY UPDATE part
Remove changes made by bug fix#8147. They strips list of insert_table_list to
only insert table, which results in error reported in bug #9728.
Added flag to Item to resolve ambigous fields reported in bug #8147.
Ensure that 'null_value' is not accessed before val() is called in FIELD() functions
Fixed initialization of key maps. This fixes some problems with keys when you have more than 64 keys
Fixed that ROLLUP don't always create a temporary table. This fix ensures that func_gconcat.test results are now predictable
