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385957a77c
This change adds CURSOR declarations inside PACKAGE BODY.
PL/SQL mode:
SET sql_mode=ORACLE;
CREATE PACKAGE BODY pkg AS
CURSOR mc0 IS SELECT c0, c1 FROM t1;
PROCEDURE p1 AS
rec mc0%ROWTYPE;
BEGIN
OPEN mc0;
FETCH mc0 INTO rec;
CLOSE mc0
END;
END;
/
SQL/PSM mode:
SET sql_mode=DEFAULT;
CREATE PACKAGE BODY pkg
mc0 CURSOR FOR SELECT c0, c1 FROM t1;
PROCEDURE p1()
BEGIN
DECLARE rec ROW TYPE OF mc0;
OPEN mc0;
FETCH mc0 INTO rec;
CLOSE mc0
END;
END;
/
PACKAGE BODY cursors like local cursors
(declared inside a FUNCTION or a PROCEDURE) support:
- OPEN/FETCH/CLOSE
- FOR rec IN cur - an explicit cursor loop
- Using a cursor row as an anchored variable data type:
* DECLARE var cur%ROWTYPE; -- sql_mode=ORACLE
* DECLARE var ROW TYPE OF cur; -- sql_mode=DEFAULT
The patch details:
- Changing various class members and function/method parameters which
store a CURSOR run-time address from "uint" to sp_rcontext_addr.
A few classes now derive from sp_rcontext_addr instead of having
a "uint m_cursor;" member.
This change uses the same idea with what we did for SP variables,
when we implemented PACKAGE BODY variables a few years ago.
- Fixing the grammar in sql_yacc.yy to allow CURSOR declarations
inside PACKAGE BODY.
- Moving the C++ code handing the "CLOSE_SYM ident" grammar
and creating an sp_instr_cclose instance from sql_yacc.yy
into a new method LEX::sp_close().
This is to have the grammar file smaller.
Also, this code has significantly changed anyway.
- Adding a new class sp_pcontext_top. It's used for the top level parse
context (of an sp_head). Note, its children contexts still use the old
class sp_pcontext.
sp_pcontext_top context additionally to sp_pcontext has:
const sp_head *m_sp; -- The pointer to the sp_head owning this context
Dynamic_array<sp_pcursor> m_member_cursors; -- PACKAGE BODY wide cursors
m_sp->m_parent->get_parse_context() is used to find the sp_pcontext
belonging to the parent PACKAGE BODY from a sp_pcontext_top instance
belonging to a PROCEDURE/FUNCTION sp_pcontext_top.
- Adding a new member in sp_rcontext:
Dynamic_array<sp_cursor*> m_member_cursors;
It's used to store run-time data of PACKAGE BODY wide cursors.
- Adding a new class sp_instr_copen2. It's used to open PACKAGE BODY cursors.
Unlike the usual cursors, PACKAGE BODY cursors:
* do not use the cursor stack (sp_rcontext::m_cstack)
* do not need a preceeding sp_instr_cpush
* do not need a following sp_instr_cpop
All cursor information such as "sp_lex_cursor" resides inside
sp_instr_copen2 itself (rather than inside sp_instr_cpush which is
used to store "sp_lex_cursor" in case of sp_instr_copen).
Note, the other cursor related instructions:
sp_instr_cfetch
sp_instr_cclose
sp_instr_cursor_copy_struct
do not need sp_instr_xxx2 counter-parts.
Thy just use sp_rcontext_addr to address cursors.
- Adding Sp_rcontext_handler_member
It's used to handle PACKAGE BODY members:
cursors and variables declared in the PACKAGE BODY,
when they are accessed from its executable initialization section:
CREATE PACKAGE BODY pkg AS
CURSOR mc0 IS SELECT c0, c1 FROM t1; -- A member (PACKAGE BODY cursor)
mv0 mc0%ROWTYPE; -- A member (PACKAGE BODY variable)
PROCEDURE p1 AS
BEGIN
-- Accessing members from here use sp_rcontext_handler_package_body
-- (members of the parent PACKAGE BODY)
OPEN mc0;
FETCH mc0 INTO mv0;
CLOSE mc0;
END;
BEGIN
-- NEW:
-- Accessing members from here use sp_rcontext_handler_member
-- (PACKAGE BODY own members)
OPEN mc0;
FETCH mc0 INTO mv0;
CLOSE mc0;
END;
/
Member variables and cursor are now marked with the "MEMBER." prefix
in the "SHOW PACKAGE BODY code" output.
Some old MTR tests have been re-recorded accordingly.
- Adding new virtual methods into Sp_rcontext_handler:
virtual const sp_variable *get_pvariable(const sp_pcontext *pctx,
uint offset) const;
virtual const sp_pcursor *get_pcursor(const sp_pcontext *pctx,
uint offset) const;
They're used from sp_instr::print() virtual implementations.
They internally calculate a proper sp_pcontext using as a parameter
the sp_pcontext pointed by sp_instr::m_ctx.
For example, Sp_handler_package_body::get_pvariable()/get_pcursor()
accesses to this sp_pcontext:
m_ctx->top_context()->m_sp->m_parent->get_parse_context(),
i.e. the parse context of the PACKAGE BODY which is the parent for
the current package PROCEDURE of FUNCTION an sp_instr belongs to.
- Adding a new method LEX::find_cursor(). It searches for a cursor in
this order:
* Local cursors in the nearst upper BEGIN/END block.
* A member cursor of the current PACKAGE BODY
(used from the PACKAGE BODY initialization section)
* A member cursor of the parrent PACKAGE BODY
(used from a package PROCEDURE or a package FUNCTION)
Adding a new method LEX::find_cursor_with_error().
In case when a cursor is not found, it automatically
raises the ER_SP_CURSOR_MISMATCH SQL condition into
the diagnostics area.
- Adding a new method sp_head::add_instr_copenX().
It creates sp_instr_copen for local cursors,
or sp_instr_copen2 for non-local cursors.
- Adding a new abstract class sp_lex_cursor_instr.
It's used a common parent class for a few sp_instr_xxx classes,
including the new sp_instr_copen2.
This change is needed to avoid code duplication.
- Adding a new protected method sp_instr::print_cmd_and_var(), to print
an instruction using this format: "command name@offset".
It's used from a few implementations of sp_instr_xxx::print(),
including sp_instr_copen2::print().
This change is also needed to avoid code duplication.
- Moving the definition of "class Sp_rcontext_handler" from item.h
into a new file sp_rcontext_handler.h
This is to maitain header dependencies easier, as well as to move
declarations not directly related to "class Item" outside of item.h
- Adding a new method sp_pcontext::frame_for_members(), to distinguish
easier between local cursors/variables and PACKAGE BODY cursors/variables.
- Fixing "struct Lex_for_loop_st" to addionally store
a const pointer to Sp_rcontext_handler, to distinguish between:
* FOR rec IN local_cursor
* FOR rec IN package_body_cursor
141 lines
4.7 KiB
C++
141 lines
4.7 KiB
C++
#ifndef SP_RCONTEXT_HANDLER_INCLUDED
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#define SP_RCONTEXT_HANDLER_INCLUDED
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/* Copyright (c) 2009, 2025, MariaDB Corporation.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
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class sp_rcontext;
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class sp_pcontext;
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class sp_pcursor;
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class sp_cursor;
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/**
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A helper class to handle the run time context of various components of SP:
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Variables:
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- local SP variables and SP parameters
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- PACKAGE BODY routine variables
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- (there will be more kinds in the future)
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Cursors:
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- static local cursors
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- static PACKAGE BODY cursors of the parent PACKAGE BODY
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- static PACKAGE BODY own cursors (when used in the executable secion)
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*/
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class Sp_rcontext_handler
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{
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public:
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virtual ~Sp_rcontext_handler() = default;
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/**
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A prefix used for SP variable names in queries:
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- EXPLAIN EXTENDED
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- SHOW PROCEDURE CODE
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Local variables and SP parameters have empty prefixes.
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Package body variables are marked with a special prefix.
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This improves readability of the output of these queries,
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especially when a local variable or a parameter has the same
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name with a package body variable.
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*/
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virtual const LEX_CSTRING *get_name_prefix() const= 0;
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// Find a parse time SP variable
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virtual const sp_variable *get_pvariable(const sp_pcontext *pctx,
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uint offset) const= 0;
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// Find a parse time SP cursor
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virtual const sp_pcursor *get_pcursor(const sp_pcontext *pctx,
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uint offset) const= 0;
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/**
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At execution time THD->spcont points to the run-time context (sp_rcontext)
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of the currently executed routine.
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Local variables store their data in the sp_rcontext pointed by thd->spcont.
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Package body variables store data in separate sp_rcontext that belongs
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to the package.
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This method provides access to the proper sp_rcontext structure,
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depending on the SP variable kind.
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*/
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virtual sp_rcontext *get_rcontext(sp_rcontext *ctx) const= 0;
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// Find a run time SP cursor
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virtual sp_cursor *get_cursor(THD *thd, uint offset) const= 0;
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};
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/*
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A handler to access local variables and cursors.
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*/
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class Sp_rcontext_handler_local final: public Sp_rcontext_handler
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{
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public:
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const LEX_CSTRING *get_name_prefix() const override;
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const sp_variable *get_pvariable(const sp_pcontext *pctx,
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uint offset) const override;
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const sp_pcursor *get_pcursor(const sp_pcontext *pctx,
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uint offset) const override;
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sp_rcontext *get_rcontext(sp_rcontext *ctx) const override;
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sp_cursor *get_cursor(THD *thd, uint offset) const override;
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};
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/*
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A handler to access parent members, e.g.:
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PACKAGE BODY variables and cursors when used in package routines.
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*/
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class Sp_rcontext_handler_package_body final :public Sp_rcontext_handler
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{
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public:
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const LEX_CSTRING *get_name_prefix() const override;
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const sp_variable *get_pvariable(const sp_pcontext *pctx,
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uint offset) const override;
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const sp_pcursor *get_pcursor(const sp_pcontext *pctx,
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uint offset) const override;
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sp_rcontext *get_rcontext(sp_rcontext *ctx) const override;
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sp_cursor *get_cursor(THD *thd, uint offset) const override;
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};
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/*
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A handler to access its own members, e.g.:
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PACKAGE BODY variables and cursors when used in
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the initialization section of PACKAGE BODY.
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*/
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class Sp_rcontext_handler_member final :public Sp_rcontext_handler
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{
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public:
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const LEX_CSTRING *get_name_prefix() const override;
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const sp_variable *get_pvariable(const sp_pcontext *pctx,
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uint offset) const override;
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const sp_pcursor *get_pcursor(const sp_pcontext *pctx,
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uint offset) const override;
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sp_rcontext *get_rcontext(sp_rcontext *ctx) const override;
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sp_cursor *get_cursor(THD *thd, uint offset) const override;
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};
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extern MYSQL_PLUGIN_IMPORT
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Sp_rcontext_handler_local sp_rcontext_handler_local;
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extern MYSQL_PLUGIN_IMPORT
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Sp_rcontext_handler_package_body sp_rcontext_handler_package_body;
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extern MYSQL_PLUGIN_IMPORT
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Sp_rcontext_handler_member sp_rcontext_handler_member;
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#endif // SP_RCONTEXT_HANDLER_INCLUDED
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