Fixed handling of default values with cached temporal functions so that the
CREATE TABLE statement now succeeds.
Fixed virtual column session cleanup.
Fixed the error message.
Added quoting of date/time values in cases when this was omitted.
Added a test case in default.test.
Updated test result files.
Optionally do table->update_default_fields() even for INSERT
that supposedly provides values for all column. Because these
"values" might be DEFAULT, which would need table->update_default_fields()
at the end.
Also set Item_default_value::used_tables() from the default expression.
Non-zero used_field() means that mysql_insert() will initialize all
fields to their default values (with restore_record()) even if
all columns are later provided with values. Because default expressions
may refer to other columns and they must be initialized.
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.
When updating a table with virtual BLOB columns, the following might
happen:
- an old record is read from the table, it has no virtual blob values
- update_virtual_fields() is run, vcol blob gets its value into the
record. But only a pointer to the value is in the table->record[0],
the value is in Field_blob::value String (but it doesn't have to be!
it can be in the record, if the column is just a copy of another
columns: ... b VARCHAR, c BLOB AS (b) ...)
- store_record(table,record[1]), old record now is in record[1]
- fill_record() prepares new values in record[0], vcol blob is updated,
new value replaces the old one in the Field_blob::value
- now both record[1] and record[0] have a pointer that points to the
*new* vcol blob value. Or record[1] has a pointer to nowhere if
Field_blob::value had to realloc.
To fix this I have introduced a new String object 'read_value' in
Field_blob. When updating virtual columns when a row has been read,
the allocated value is stored in 'read_value' instead of 'value'. The
allocated blobs for the new row is stored in 'value' as before.
I also made, as a safety precaution, the insert delayed handling of
blobs more general by using value to store strings instead of the
record. This ensures that virtual functions on delayed insert should
work in as in the case of normal insert.
Triggers are now properly updating the read, write and vcol maps for used
fields. This means that we don't need VCOL_UPDATE_FOR_READ_WRITE anymore
and there is no need for any other special handling of triggers in
update_virtual_fields().
To be able to test how many times virtual fields are invoked, I also
relaxed rules that one can use local (@) variables in DEFAULT and non
persistent virtual field expressions.
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().
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.
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.
That is, when the precision of DEFAULT NOW() is less than
the precision of the column, do not convert it to unireg_check,
use the new approach where DEFAULT is tryly an expression.
* revert part of the db7edfe that moved calculations from
fix_fields to val_str for Item_func_sysconst and descendants
* mark session state dependent functions in check_vcol_func_processor()
* re-run fix_fields for all such functions for every statement
* fix CURRENT_USER/CURRENT_ROLE not to use Name_resolution_context
(that is allocated on the stack in unpack_vcol_info_from_frm())
Note that NOW(), CURDATE(), etc use lazy initialization and do *not*
force fix_fields to be re-run. The rule is:
* lazy initialization is *not* allowed, if it changes metadata (so,
e.g. DAYNAME() cannot use it)
* lazy initialization is *preferrable* if it has side effects (e.g.
NOW() sets thd->time_zone_used=1, so it's better to do it when
the value of NOW is actually needed, not when NOW is simply prepared)
- Adding SHOW CREATE TABLE into all DEFAULT tests,
to cover need_parentheses_in_default() for all items
- Fixing a few items not to print parentheses in DEFAULT:
spatial function-alike predicates, IS_IPV4 and IS_IPV6 functions,
COLUMN_CHECK() and COLUMN_EXISTS().
- Force usage of () around complex DEFAULT expressions
- Give error if DEFAULT expression contains invalid characters
- Don't use const_charset_conversion for stored Item_func_sysconf expressions
as the result is not constaint over different executions
- Fixed Item_func_user() to not store calculated value in str_value
MDEV-10134 Add full support for DEFAULT
- Added support for using tables with MySQL 5.7 virtual fields,
including MySQL 5.7 syntax
- Better error messages also for old cases
- CREATE ... SELECT now also updates timestamp columns
- Blob can now have default values
- Added new system variable "check_constraint_checks", to turn of
CHECK constraint checking if needed.
- Removed some engine independent tests in suite vcol to only test myisam
- Moved some tests from 'include' to 't'. Should some day be done for all tests.
- FRM version increased to 11 if one uses virtual fields or constraints
- Changed to use a bitmap to check if a field has got a value, instead of
setting HAS_EXPLICIT_VALUE bit in field flags
- Expressions can now be up to 65K in total
- Ensure we are not refering to uninitialized fields when handling virtual fields or defaults
- Changed check_vcol_func_processor() to return a bitmap of used types
- Had to change some functions that calculated cached value in fix_fields to do
this in val() or getdate() instead.
- store_now_in_TIME() now takes a THD argument
- fill_record() now updates default values
- Add a lookahead for NOT NULL, to be able to handle DEFAULT 1+1 NOT NULL
- Automatically generate a name for constraints that doesn't have a name
- Added support for ALTER TABLE DROP CONSTRAINT
- Ensure that partition functions register virtual fields used. This fixes
some bugs when using virtual fields in a partitioning function
Print default values for BLOB's.
This is a part commit for automatic changes to make the real commit smaller.
All changes here are related to that we now print DEFAULT NULL for blob and
text fields, like we do for all other fields.
