* sys fields are NULL by default (with exceptions, see comment about NOT_NULL_FLAG in #77);
* error codes renamed, messages cleared out;
* SHOW CREATE TABLE fixed;
* set_max() fix;
* redundant flag setters/getters removed;
* flags are set in sql_yacc.yy, redundant copy_info_about_generated_fields() eliminated.
Syntax extension: TIMESTAMP/TRANSACTION keyword can be used before FROM ... TO, BETWEEN ... AND.
Example:
SELECT * FROM t1 FOR SYSTEM_TIME TIMESTAMP FROM '1-1-1' TO NOW();
Closes#27
Working features:
CREATE OR REPLACE [TEMPORARY] SEQUENCE [IF NOT EXISTS] name
[ INCREMENT [ BY | = ] increment ]
[ MINVALUE [=] minvalue | NO MINVALUE ]
[ MAXVALUE [=] maxvalue | NO MAXVALUE ]
[ START [ WITH | = ] start ] [ CACHE [=] cache ] [ [ NO ] CYCLE ]
ENGINE=xxx COMMENT=".."
SELECT NEXT VALUE FOR sequence_name;
SELECT NEXTVAL(sequence_name);
SELECT PREVIOUS VALUE FOR sequence_name;
SELECT LASTVAL(sequence_name);
SHOW CREATE SEQUENCE sequence_name;
SHOW CREATE TABLE sequence_name;
CREATE TABLE sequence-structure ... SEQUENCE=1
ALTER TABLE sequence RENAME TO sequence2;
RENAME TABLE sequence TO sequence2;
DROP [TEMPORARY] SEQUENCE [IF EXISTS] sequence_names
Missing features
- SETVAL(value,sequence_name), to be used with replication.
- Check replication, including checking that sequence tables are marked
not transactional.
- Check that a commit happens for NEXT VALUE that changes table data (may
already work)
- ALTER SEQUENCE. ANSI SQL version of setval.
- Share identical sequence entries to not add things twice to table list.
- testing insert/delete/update/truncate/load data
- Run and fix Alibaba sequence tests (part of mysql-test/suite/sql_sequence)
- Write documentation for NEXT VALUE / PREVIOUS_VALUE
- NEXTVAL in DEFAULT
- Ensure that NEXTVAL in DEFAULT uses database from base table
- Two NEXTVAL for same row should give same answer.
- Oracle syntax sequence_table.nextval, without any FOR or FROM.
- Sequence tables are treated as 'not read constant tables' by SELECT; Would
be better if we would have a separate list for sequence tables so that
select doesn't know about them, except if refereed to with FROM.
Other things done:
- Improved output for safemalloc backtrack
- frm_type_enum changed to Table_type
- Removed lex->is_view and replaced with lex->table_type. This allows
use to more easy check if item is view, sequence or table.
- Added table flag HA_CAN_TABLES_WITHOUT_ROLLBACK, needed for handlers
that want's to support sequences
- Added handler calls:
- engine_name(), to simplify getting engine name for partition and sequences
- update_first_row(), to be able to do efficient sequence implementations.
- Made binlog_log_row() global to be able to call it from ha_sequence.cc
- Added handler variable: row_already_logged, to be able to flag that the
changed row is already logging to replication log.
- Added CF_DB_CHANGE and CF_SCHEMA_CHANGE flags to simplify
deny_updates_if_read_only_option()
- Added sp_add_cfetch() to avoid new conflicts in sql_yacc.yy
- Moved code for add_table_options() out from sql_show.cc::show_create_table()
- Added String::append_longlong() and used it in sql_show.cc to simplify code.
- Added extra option to dd_frm_type() and ha_table_exists to indicate if
the table is a sequence. Needed by DROP SQUENCE to not drop a table.
Fixed that the Column_definition::pack_flag member corresponding to
ROW-type SP variables and their fields was not properly initialized.
This lead to sporadic test failures. Valgrind complained about jumps
depending on uninitialized value in VALGRIND builds.
This patch makes sure that sp_head::fill_spvar_definition() is always
called for ROW variables and their fields.
Additionally, fixed that a function with a scalar parameter
erroneously acceptes ROWs with one fields. Now an error is returned.
Implementing cursor%ROWTYPE variables, according to the task description.
This patch includes a refactoring in how sp_instr_cpush and sp_instr_copen
work. This is needed to implement MDEV-10598 later easier, to allow variable
declarations go after cursor declarations (which is currently not allowed).
Before this patch, sp_instr_cpush worked as a Query_arena associated with
the cursor. sp_instr_copen::execute() switched to the sp_instr_cpush's
Query_arena when executing the cursor SELECT statement.
Now the Query_arena associated with the cursor is stored inside an instance
of a new class sp_lex_cursor (a LEX descendand) that contains the cursor SELECT
statement.
This simplifies the implementation, because:
- It's easier to follow the code when everything related to execution
of the cursor SELECT statement is stored inside the same sp_lex_cursor
object (rather than distributed between LEX and sp_instr_cpush).
- It's easier to link an sp_instr_cursor_copy_struct to
sp_lex_cursor rather than to sp_instr_cpush.
- Also, it allows to perform sp_instr_cursor_copy_struct::exec_core()
without having a pointer to sp_instr_cpush, using a pointer to sp_lex_cursor
instead. This will be important for MDEV-10598, because sp_instr_cpush will
happen *after* sp_instr_cursor_copy_struct.
After MDEV-10598 is done, this declaration:
DECLARE
CURSOR cur IS SELECT * FROM t1;
rec cur%ROWTYPE;
BEGIN
OPEN cur;
FETCH cur INTO rec;
CLOSE cur;
END;
will generate about this code:
+-----+--------------------------+
| Pos | Instruction |
+-----+--------------------------+
| 0 | cursor_copy_struct rec@0 | Points to sp_cursor_lex through m_lex_keeper
| 1 | set rec@0 NULL |
| 2 | cpush cur@0 | Points to sp_cursor_lex through m_lex_keeper
| 3 | copen cur@0 | Points to sp_cursor_lex through m_cursor
| 4 | cfetch cur@0 rec@0 |
| 5 | cclose cur@0 |
| 6 | cpop 1 |
+-----+--------------------------+
Notice, "cursor_copy_struct" and "set" will go before "cpush".
Instructions at positions 0, 2, 3 point to the same sp_cursor_lex instance.
Adding methods:
- LEX::sp_while_loop_expression()
- LEX::sp_while_loop_finalize()
to reuse code between sql_yacc.yy and sql_yacc_ora.yy.
FOR loop will also reuse these methods.
Moving similar code from sql_yacc.yy and sql_yacc_ora.yy to methods:
LEX::maybe_start_compound_statement()
LEX::sp_push_loop_label()
LEX::sp_push_loop_empty_label()
LEX::sp_pop_loop_label()
LEX::sp_pop_loop_empty_label()
The EXIT statement will also reuse this code.
Moving the code from *.yy to methods:
LEX::sp_change_context()
LEX::sp_leave_statement()
LEX::sp_iterate_statement()
to reuse the same code between LEAVE and ITERATE statements.
EXIT statement will also reuse the same code.
Part 12: No parentheses if no arguments
Now "CREATE PROCEDURE p1 AS" is supported with no parentheses after the name.
Note, "CREATE FUNCTION f1 AS" is not supported yet, due to grammar conflict
with UDFs. Functions will be done in a separate patch.
Part 9: EXCEPTION handlers
- Adding exception handler syntax:
WHEN exception_name THEN statement
- Adding EXCEPTION section intoi the top BEGIN..END SP block.
Note, currently EXCEPTION goes in the beginning of the top BEGIN..END
SP block.
TODO:
- add EXCEPTION section into inner blocks
- move EXCEPTION to the end of the block
