Problem: Item_param::basic_const_item() returned true when fixed==false.
This unexpected combination made Item::const_charset_converter() crash
on asserts.
Fix:
- Changing all Item_param::set_xxx() to set "fixed" to true.
This fixes the problem.
- Additionally, changing all Item_param::set_xxx() to set
Item_param::item_type, to avoid duplicate code, and for consistency,
to make the code symmetric between different constant types.
Before this patch only set_null() set item_type.
- Moving Item_param::state and Item_param::item_type from public to private,
to make sure easier that these members are in sync with "fixed" and to
each other.
- Adding a new argument "unsigned_arg" to Item::set_decimal(),
and reusing it in two places instead of duplicate code.
- Adding a new method Item_param::fix_temporal() and reusing it in two places.
- Adding methods has_no_value(), has_long_data_value(), has_int_value(),
instead of direct access to Item_param::state.
in Item_partition_func_safe_string(THD *thd, const char *name_arg,
uint length, CHARSET_INFO *cs= NULL), the 'name_arg' is the value
of the string constant and 'length' is the length of this constant,
so length == strlen(name_arg).
The problem happened because Item_ident_for_show::field_type() always
returned MYSQL_TYPE_DOUBLE and ignored the actual data type of the
referenced Field. As a result, the execution always used
Item_ident_for_show::val_real() to send the default value of the field,
so most default values for non-numeric types were displayed as '0'.
This patch:
1. Cleanup:
a. Removes Send_field::charsetnr, as it's been unused since
introduction of Item::charset_for_protocol() in MySQL-5.5.
b. Adds the "const" qualifier to Field::char_length().
This is needed for (5.a), see below.
2. Introduces a new virtual method Type_handler::charset_for_protocol(),
returning item->collation.collation for string data types, or
&my_charset_bin for non-string data types.
3. Changes Item::charset_for_protocol() from virtual to non-virtual.
It now calls type_handler()->charset_for_protocol().
As a good side effect, duplicate code in Item::charset_for_protocol() and
Item_temporal_hybrid_func::charset_for_protocol() is now gone.
4. Fixes Item_ident_for_show::field_type() to correctly return
its data type according to the data type of the referenced field.
This actually fixes the problem reported in MDEV-11672.
Now the default value is sent using a correct method, e.g.
val_str() for VARCHAR/TEXT, or val_int() for INT/BIGINT.
This required additional changes:
a. in DBUG_ASSERT in Protocol::store(const char *,size_t,CHARSET_INFO),
This method is now used by mysqld_list_fields(), which
(unlike normal SELECT queries) does not set
field_types/field_pos/field_count.
b. Item_ident_for_show::Item_ident_for_show() now set standard attributes
(collation, decimals, max_length, unsigned_flag) according to the
referenced field, to make charset_for_protocol() return the correct
value and to make mysqld_list_fields() correctly send default
values.
5. In order to share the code between Item_field::set_field() and
Item_ident_for_show::Item_ident_for_show():
a. Introduces a new method Type_std_attributes::set(const Field*)
b. To make (a) possible, moves Item::fix_char_length() from Item
to Type_std_attributes, also moves char_to_byte_length_safe()
from item.h to sql_type.h
c. Additionally, moves Item::fix_length_and_charset() and
Item::max_char_length() from Item to Type_std_attributes.
This is not directly needed for the fix and is done just for symmetry
with fix_char_length(), as these three methods are directly related
to each other.
This patch fixes a number of data type aggregation problems in IN and CASE:
- MDEV-11497 Wrong result for (int_expr IN (mixture of signed and unsigned expressions))
- MDEV-11514 IN with a mixture of TIME and DATETIME returns a wrong result
- MDEV-11554 Wrong result for CASE on a mixture of signed and unsigned expressions
- MDEV-11555 CASE with a mixture of TIME and DATETIME returns a wrong result
1. The problem reported in MDEV-11514 and MDEV-11555 was in the wrong assumption
that items having the same cmp_type() can reuse the same cmp_item instance.
So Item_func_case and Item_func_in used a static array of cmp_item*,
one element per one XXX_RESULT.
TIME and DATETIME cannot reuse the same cmp_item, because arguments of
these types are compared very differently. TIME and DATETIME must have
different instances in the cmp_item array. Reusing the same cmp_item
for TIME and DATETIME leads to unexpected result and unexpected warnings.
Note, after adding more data types soon (e.g. INET6), the problem would
become more serious, as INET6 will most likely have STRING_RESULT, but
it won't be able to reuse the same cmp_item with VARCHAR/TEXT.
This patch introduces a new class Predicant_to_list_comparator,
which maintains an array of cmp_items, one element per distinct
Type_handler rather than one element per XXX_RESULT.
2. The problem reported in MDEV-11497 and MDEV-11554 happened because
Item_func_in and Item_func_case did not take into account the fact
that UNSIGNED and SIGNED values must be compared as DECIMAL rather than INT,
because they used item_cmp_type() to aggregate the arguments.
The relevant code now resides in Predicant_to_list_comparator::add_value()
and uses Type_handler_hybrid_field_type::aggregate_for_comparison(),
like Item_func_between does.
This patch:
- Adds a new virtual method Type_handler::Item_get_cache
- Splits moves Item_cache::get_cache() into the new method, every
"case XXX_RESULT" to the corresponding Type_handler_xxx::Item_get_cache.
- Adds Item::get_cache as a convenience wrapper, to make the caller code
shorter.
- Changes the last argument of Arg_comparator::cache_converted_constant()
from Item_result to "const Type_handler *".
- Removes subselect_engine::cmp_type, subselect_engine::res_type,
subselect_engine::res_field_type and derives subselect_engine
from Type_handler_hybrid_field_type instead.
- Makes Type_handler_varchar public, as it's now needed as the
default data type handler for subselect_engine.
Also fixes:
MDEV-11331 Wrong result for INSERT INTO t1 (datetime_field) VALUES (hybrid_function_of_TIME_data_type)
MDEV-11333 Expect "Impossible where condition" for WHERE timestamp_field>=DATE_ADD(TIMESTAMP'9999-01-01 00:00:00',INTERVAL 1000 YEAR)
This patch does the following:
1. Splits the function Item::save_in_field() into pieces:
- Item::save_str_in_field()
- Item::save_real_in_field()
- Item::save_decimal_in_field()
- Item::save_int_in_field()
2. Adds the missing "no_conversion" parameters to
Item::save_time_in_field() and Item::save_date_in_field(),
so this parameter is now correctly passed to
set_field_to_null_with_conversions().
This fixes the problem reported in 11333.
3. Introduces a new virtual method Type_handler::Item_save_in_field()
and uses the methods Item::save_xxx_in_field() from the implementations
of Type_handler_xxx::Item_save_in_field().
These changes additionally fix the problem reported in MDEV-11331,
as the old code erroneously handled expressions like
COALESE(datetime-expression) through the STRING_RESULT branch of
Item::save_in_field() and therefore they looked like string type expressions
for the target fields. Now such expressions are correctly handled by
Item::save_date_in_field().
The patch for bug mdev-10882 tried to fix it by providing an
implementation of the virtual method build_clone for the class
Item_cache. It's turned out that it is not easy provide a valid
implementation for Item_cache::build_clone(). At the same time
if the condition that can be pushed into a materialized view
contains a cached item this item can be substituted for a basic
constant of the same value. In such a way we can avoid building
proper clones for Item_cache objects when constructing pushdown
conditions.
otherwise we'd need to store sql_mode *per vcol*
(consider CREATE INDEX...) and how SHOW CREATE TABLE would
support that?
Additionally, get rid of vcol::expr_str, just to make sure
the string is always generated and never leaked in the
original form.
Different fix. Don't allow Item_func_sp to be evaluated unless
all tables are prelocked.
Extend the test case to make sure Item_func_sp::val_str is called
(the table must have at least one row for that).
This patch adds DEFAULT as a possible dynamic SQL parameter, e.g.:
EXECUTE IMMEDIATE 'INSERT INTO t1 (column) VALUES(?)' USING DEFAULT;
EXECUTE IMMEDIATE 'UPDATE t1 SET column=?' USING DEFAULT;
and for similar PREPARE..EXECUTE queries.
This is done for symmetry with the STMT_INDICATOR_DEFAULT indicator in
the client-server PS protocol.
The changes include:
- Allowing DEFAULT as a possible option in execute USING clause (sql_yacc.yy)
- Adding "virtual bool Item::save_in_param(THD *thd, Item_param *param)",
because "normal" items (that have real values) and Item_default_value
have now different actions when assigning itself as an Item_param value.
- Fixing switch() statements in a few Item_param methods not to have "default",
because it was easy to forget to add a new "case" when adding a new XXX_VALUE
value into the enum Item_param::enum_item_param_state.
This is important, as we'll be adding new values soon, e.g. for MDEV-11359.
Removing "default" helped to find and report bugs MDEV-11361 and MDEV-11362,
because DECIMAL_VALUE is obviously not properly handled in some cases.
There were no implementations for the virtual functions
exclusive_dependence_on_table_processor and
exclusive_dependence_on_table_processor. As a result
the procedure pushdown_cond_for_derived erroneously
detected some conditions with outer references as pushable
into materialized view / derived table.
In a general case the conditions with outer fields cannot
be pushed into materialized views / derived tables.
However if the outer field in the condition refers to a
single row table then the condition may be pushable.
In this case a special care should be taken for outer
fields when pushing the condition into a materialized view /
derived table.
MDEV-10780 Server crashes in in create_tmp_table
MDEV-11265 Access defied when CREATE VIIEW v1 AS SELECT DEFAULT(column) FROM t1
Item_default_value and Item_insert_value erroneously derive from Item_field
but forgot to override some methods that apply only to true fields,
so the server code mixes Item_{default|insert}_value instances with real
table fields (i.e. true Item_field) in some cases.
Overriding a few methods to avoid this.
TODO: we should eventually derive Item_default_value (and Item_insert_value)
directly from Item, as they don't really need the entire Item_field,
Item_ident and Item_result_field functionality.
Only the member "Field *field" related functionality is actually needed,
like val_xxx(), is_null(), get_geometry_type(), charset_for_protocol(), etc.
for materialized views and derived tables: there were no
push-down if the view was defined as union of selects
without aggregation. Added test cases with such unions.
Adjusted result files after the merge of the code for mdev-9197.
Adding Converter_double_to_longlong and reusing it in:
1. Field_longlong::store(double nr)
2. Field_double::val_int()
3. Item::val_int_from_real()
4. Item_dyncol_get::val_int()
As a good side efferct, now overflow in conversion in the mentioned
val_xxx() methods return exactly the same warning.
