This patch adds support for SYS_REFCURSOR (a weakly typed cursor)
for both sql_mode=ORACLE and sql_mode=DEFAULT.
Works as a regular stored routine variable, parameter and return value:
- can be passed as an IN parameter to stored functions and procedures
- can be passed as an INOUT and OUT parameter to stored procedures
- can be returned from a stored function
Note, strongly typed REF CURSOR will be added separately.
Note, to maintain dependencies easier, some parts of sql_class.h
and item.h were moved to new header files:
- select_results.h:
class select_result_sink
class select_result
class select_result_interceptor
- sp_cursor.h:
class sp_cursor_statistics
class sp_cursor
- sp_rcontext_handler.h
class Sp_rcontext_handler and its descendants
The implementation consists of the following parts:
- A new class sp_cursor_array deriving from Dynamic_array
- A new class Statement_rcontext which contains data shared
between sub-statements of a compound statement.
It has a member m_statement_cursors of the sp_cursor_array data type,
as well as open cursor counter. THD inherits from Statement_rcontext.
- A new data type handler Type_handler_sys_refcursor in plugins/type_cursor/
It is designed to store uint16 references -
positions of the cursor in THD::m_statement_cursors.
- Type_handler_sys_refcursor suppresses some derived numeric features.
When a SYS_REFCURSOR variable is used as an integer an error is raised.
- A new abstract class sp_instr_fetch_cursor. It's needed to share
the common code between "OPEN cur" (for static cursors) and
"OPER cur FOR stmt" (for SYS_REFCURSORs).
- New sp_instr classes:
* sp_instr_copen_by_ref - OPEN sys_ref_curor FOR stmt;
* sp_instr_cfetch_by_ref - FETCH sys_ref_cursor INTO targets;
* sp_instr_cclose_by_ref - CLOSE sys_ref_cursor;
* sp_instr_destruct_variable - to destruct SYS_REFCURSOR variables when
the execution goes out of the BEGIN..END block
where SYS_REFCURSOR variables are declared.
- New methods in LEX:
* sp_open_cursor_for_stmt - handles "OPEN sys_ref_cursor FOR stmt".
* sp_add_instr_fetch_cursor - "FETCH cur INTO targets" for both
static cursors and SYS_REFCURSORs.
* sp_close - handles "CLOSE cur" both for static cursors and SYS_REFCURSORs.
- Changes in cursor functions to handle both static cursors and SYS_REFCURSORs:
* Item_func_cursor_isopen
* Item_func_cursor_found
* Item_func_cursor_notfound
* Item_func_cursor_rowcount
- A new system variable @@max_open_cursors - to limit the number
of cursors (static and SYS_REFCURSORs) opened at the same time.
Its allowed range is [0-65536], with 50 by default.
- A new virtual method Type_handler::can_return_bool() telling
if calling item->val_bool() is allowed for Items of this data type,
or if otherwise the "Illegal parameter for operation" error should be raised
at fix_fields() time.
- New methods in Sp_rcontext_handler:
* get_cursor()
* get_cursor_by_ref()
- A new class Sp_rcontext_handler_statement to handle top level statement
wide cursors which are shared by all substatements.
- A new virtual method expr_event_handler() in classes Item and Field.
It's needed to close (and make available for a new OPEN)
unused THD::m_statement_cursors elements which do not have any references
any more. It can happen in various moments in time, e.g.
* after evaluation parameters of an SQL routine
* after assigning a cursor expression into a SYS_REFCURSOR variable
* when leaving a BEGIN..END block with SYS_REFCURSOR variables
* after setting OUT/INOUT routine actual parameters from formal
parameters.
|
||
|---|---|---|
| .. | ||
| charsets | ||
| CMakeLists.txt | ||
| errmsg-utf8.txt | ||
| insert_translations_into_errmsg.py | ||
| README.md | ||
A quicker way for adding new language translations to the errmsg-utf8.txt file
Summary
To generate a new language translation of MariaDB use the following pull request (PR) as a template for your work:
You will notice as part of your translation work, you will have to add your language translations to the file sql/share/errmsg-utf8.txt which is found in the current directory. This file is long with many sections which can make the translation work tedious. In this README, we explain a procedure and provide a script insert_translations_into_errmsg.py that cuts down the amount of tedium in accomplishing the task.
Procedure
-
Start by grepping out all the english translations from errmsg-utf8.txt using the following grep command, and redirecting the output to a file:
grep -P "^\s*eng\s" errmsg-utf8.txt > all_english_text_in_errmsg-utf8.txt
-
Next use Google translate to obtain a translation of this file. Google translate provides the ability to upload whole files for translation. For example, this technique was used to obtain Swahili translations which yielded a file with output similar to the below (output is truncated for clarity):
sw "hashchk" sw "isamchk" sw "LA" sw "NDIYO" sw "Haiwezi kuunda faili '% -.200s' (kosa: %iE)" sw "Haiwezi kuunda jedwali %
s.%s (kosa: %iE)" sw "Haiwezi kuunda hifadhidata '% -.192s' (kosa: %iE)" sw "Haiwezi kuunda hifadhidata '% -.192s'; hifadhidata ipo"
Note that Google translate removes the leading whitespace in the translation file it generates. DO NOT add that leading whitespace back!
-
Give the translated file an appropriate name (e.g.
all_swahili_text_in_errmsg-utf8.txt) and store it in the same directory witherrmsg-utf8.txtandall_english_text_in_errmsg-utf8.txt. These 3 files will be used by the script insert_translations_into_errmsg.py. -
Proof check the auto-translations in the file you downloaded from Google translate. Note that Google might ommit formating information that will cause the compilation of MariaDB to fail, so pay attention to these.
-
Reintegrate these translations into the errmsg-utf8.txt by running the insert_translations_into_errmsg.py script as follows:
chmod ugo+x insert_translations_into_errmsg.py # Make the script executable if it is not.
./insert_translations_into_errmsg.py <errmsg-utf8.txt file>
For example, for the swahili translation, we ran the following:
./insert_translations_into_errmsg.py errmsg-utf8.txt all_english_text_in_errmsg-utf8.txt all_swahili_text_in_errmsg-utf8.txt
The script uses the
errmsg-utf8.txtfile and the grepped english file to keep track of each new translation. It then creates a file in the same directory aserrmsg-utf8.txtwith the nameerrmsg-utf8-with-new-language.txt. -
Check that the reintegration of the new translations into
errmsg-utf8-with-new-language.txtwent OK, and if it did, renameerrmsg-utf8-with-new-language.txttoerrmsg-utf8.txt:mv errmsg-utf8-with-new-language.txt errmsg-utf8.txt
-
In the header of errmsg-utf8.txt make sure to add your language long form to short form mapping. E.g. for Swahili, add:
swahili=sw