> ------------------------------------------------------------
> revno: 2792
> revision-id: sergey.glukhov@sun.com-20090703083500-jq8vhw0tqr37j7te
> parent: bernt.johnsen@sun.com-20090703083610-o7l4s8syz05rc4w0
> committer: Sergey Glukhov <Sergey.Glukhov@sun.com>
> branch nick: mysql-5.0-bugteam
> timestamp: Fri 2009-07-03 13:35:00 +0500
> message:
> Bug#45806 crash when replacing into a view with a join!
> The crash happend because for views which are joins
> we have table_list->table == 0 and
> table_list->table->'any method' call leads to crash.
> The fix is to perform table_list->table->file->extra()
> method for all tables belonging to view.
The crash happend because for views which are joins
we have table_list->table == 0 and
table_list->table->'any method' call leads to crash.
The fix is to perform table_list->table->file->extra()
method for all tables belonging to view.
with a "HAVING" clause though query works
SELECT from views defined like:
CREATE VIEW v1 (view_column)
AS SELECT c AS alias FROM t1 HAVING alias
fails with an error 1356:
View '...' references invalid table(s) or column(s)
or function(s) or definer/invoker of view lack rights
to use them
CREATE VIEW form with a (column list) substitutes
SELECT column names/aliases with names from a
view column list.
However, alias references in HAVING clause was
not substituted.
The Item_ref::print function has been modified
to write correct aliased names of underlying
items into VIEW definition generation/.frm file.
Problem: executing queries like "ALTER TABLE view1;" we don't
check new view's name (which is not specified),
that leads to server crash.
Fix: do nothing (to be consistent with the behaviour for tables)
in such cases.
+ Fix for Bug#43114 wait_until_count_sessions too restrictive, random PB failures
+ Removal of a lot of other weaknesses found
+ modifications according to review
an error
Even after the fix for bug 28701 visible behaviors of
SELECT FROM a view and SELECT FROM a regular table are
little bit different:
1. "SELECT FROM regular table USE/FORCE/IGNORE(non
existent index)" fails with a "ERROR 1176 (HY000):
Key '...' doesn't exist in table '...'"
2. "SELECT FROM view USING/FORCE/IGNORE(any index)" fails
with a "ERROR 1221 (HY000): Incorrect usage of
USE/IGNORE INDEX and VIEW". OTOH "SHOW INDEX FROM
view" always returns empty result set, so from the point
of same behaviour view we trying to use/ignore non
existent index.
To harmonize the behaviour of USE/FORCE/IGNORE(index)
clauses in SELECT from a view and from a regular table the
"ERROR 1221 (HY000): Incorrect usage of USE/IGNORE INDEX
and VIEW" message has been replaced with the "ERROR 1176
(HY000): Key '...' doesn't exist in table '...'" message
like for tables and non existent keys.
A string buffers which were included in the 'view' data structure
were allocated on the stack, causing an invalid pointer when used
after the function returned.
The fix: use copy of values for view->md5 & view->queries
View definition as SELECT ... FROM DUAL WHERE ... has
valid syntax, but use of such view in SELECT or
SHOW CREATE VIEW syntax causes unexpected syntax error.
Server omits FROM DUAL clause when storing view body
string in a .frm file for further evaluation.
However, syntax of SELECT-witout-FROM query is more
restrictive than SELECT FROM DUAL syntax, and doesn't
allow the WHERE clause.
NOTE: this syntax difference is not documented.
View registration procedure has been modified to
preserve original structure of view's body.
suite)
Under some circumstances a combination of aggregate functions and
GROUP BY in a SELECT query over a VIEW could lead to incorrect
calculation of the result type of the aggregate function. This in
turn could result in incorrect results, or assertion failures on debug
builds.
Fixed by changing the logic in Item_sum_hybrid::fix_fields() so that
the argument's item is dereferenced before calling its type() method.
a table name.
The problem was that fill_defined_view_parts() did not return
an error if a table is going to be altered. That happened if
the table was already in the table cache. In that case,
open_table() returned non-NULL value (valid TABLE-instance from
the cache).
The fix is to ensure that an error is thrown even if the table
is in the cache.
(This is a backport of the original patch for 5.1)
The problem is that when a stored procedure is being parsed for
the first execution, the body is copied to a temporary buffer
which is disregarded sometime after the statement is parsed.
And during this parsing phase, the rule for CREATE VIEW was
holding a reference to the string being parsed for use during
the execution of the CREATE VIEW statement, leading to invalid
memory access later.
The solution is to allocate and copy the SELECT of a CREATE
VIEW statement using the thread memory root, which is set to
the permanent arena of the stored procedure.
a table name.
The problem was that fill_defined_view_parts() did not return
an error if a table is going to be altered. That happened if
the table was already in the table cache. In that case,
open_table() returned non-NULL value (valid TABLE-instance from
the cache).
The fix is to ensure that an error is thrown even if the table
is in the cache.
but not collation.
The problem here was that text literals in a view were always
dumped with character set introducer. That lead to loosing
collation information.
The fix is to dump character set introducer only if it was
in the original query. That is now possible because there
is no problem any more of loss of character set of string
literals in views -- after WL#4052 the view is dumped
in the original character set.
or trigger crashes server
Under some circumstances a combination of VIEWs, subselects with outer
references and PS/SP/triggers could lead to use of uninitialized memory
and server crash as a result.
Fixed by changing the code in Item_field::fix_fields() so that in cases
when the field is a VIEW reference, we first check whether the field
is also an outer reference, and mark it appropriately before returning.
value when inserting into a view.
The mysql_prepare_insert function checks all fields of the target table that
directly or indirectly (through a view) are specified in the INSERT
statement to have a default value. This check can be skipped if the INSERT
statement doesn't mention any insert fields. In case of a view this allows
fields that aren't mentioned in the view to bypass the check.
Now fields of the target table are always checked to have a default value
when insert goes into a view.
The following clarification should be made in The Manual:
Standard SQL is quite clear that, if new columns are added
to a table after a view on that table is created with
"select *", the new columns will not become part of the view.
In all cases, the view definition (view structure) is frozen
at CREATE time, so changes to the underlying tables do not
affect the view structure.
When storing the VIEW the CREATE VIEW command is reconstructed
from the parse tree. While constructing the command string
the index hints specified should also be printed.
Fixed by adding code to print the index hints when printing a
table in the FROM clause.
information schema table.
The get_schema_views_record() function fills records in the view table of
the informations schema with data about given views. Among other info
the is_updatable flag is set. But the check whether the view is updatable or
not wasn't covering all cases thus sometimes providing wrong info.
This might led to a user confusion.
Now the get_schema_views_record function additionally calls to the
view->can_be_merge() function to find out whether the view can be updated or
not.
This bug may manifest itself for select queries over a multi-table view
that includes an ORDER BY clause in its definition. If the select list of
the query contains references to the same view column with different
aliases the names of the columns in the result output will be nevertheless
the same, coinciding with one of the alias.
The bug happened because the method Item_ref::get_tmp_table_item that
was inherited by the class Item_direct_view_ref ignored the fact that
the name of the view column reference must be inherited by the fields
of the temporary table that was created in order to get the result rows
sorted.
- BUG#11986: Stored routines and triggers can fail if the code
has a non-ascii symbol
- BUG#16291: mysqldump corrupts string-constants with non-ascii-chars
- BUG#19443: INFORMATION_SCHEMA does not support charsets properly
- BUG#21249: Character set of SP-var can be ignored
- BUG#25212: Character set of string constant is ignored (stored routines)
- BUG#25221: Character set of string constant is ignored (triggers)
There were a few general problems that caused these bugs:
1. Character set information of the original (definition) query for views,
triggers, stored routines and events was lost.
2. mysqldump output query in client character set, which can be
inappropriate to encode definition-query.
3. INFORMATION_SCHEMA used strings with mixed encodings to display object
definition;
1. No query-definition-character set.
In order to compile query into execution code, some extra data (such as
environment variables or the database character set) is used. The problem
here was that this context was not preserved. So, on the next load it can
differ from the original one, thus the result will be different.
The context contains the following data:
- client character set;
- connection collation (character set and collation);
- collation of the owner database;
The fix is to store this context and use it each time we parse (compile)
and execute the object (stored routine, trigger, ...).
2. Wrong mysqldump-output.
The original query can contain several encodings (by means of character set
introducers). The problem here was that we tried to convert original query
to the mysqldump-client character set.
Moreover, we stored queries in different character sets for different
objects (views, for one, used UTF8, triggers used original character set).
The solution is
- to store definition queries in the original character set;
- to change SHOW CREATE statement to output definition query in the
binary character set (i.e. without any conversion);
- introduce SHOW CREATE TRIGGER statement;
- to dump special statements to switch the context to the original one
before dumping and restore it afterwards.
Note, in order to preserve the database collation at the creation time,
additional ALTER DATABASE might be used (to temporary switch the database
collation back to the original value). In this case, ALTER DATABASE
privilege will be required. This is a backward-incompatible change.
3. INFORMATION_SCHEMA showed non-UTF8 strings
The fix is to generate UTF8-query during the parsing, store it in the object
and show it in the INFORMATION_SCHEMA.
Basically, the idea is to create a copy of the original query convert it to
UTF8. Character set introducers are removed and all text literals are
converted to UTF8.
This UTF8 query is intended to provide user-readable output. It must not be
used to recreate the object. Specialized SHOW CREATE statements should be
used for this.
The reason for this limitation is the following: the original query can
contain symbols from several character sets (by means of character set
introducers).
Example:
- original query:
CREATE VIEW v1 AS SELECT _cp1251 'Hello' AS c1;
- UTF8 query (for INFORMATION_SCHEMA):
CREATE VIEW v1 AS SELECT 'Hello' AS c1;
