Details
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Technical task
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.3(EOL)
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10.2.2-3, 10.2.2-1, 10.2.2-2, 10.2.2-4, 10.1.18
Description
This task is intended to simplify the work for CREATE PACKAGE (see MDEV-10591), as well as to fix minor known problems in the underlying parser grammar.
There are a few difficulties in the grammar for CREATE for VIEW, TRIGGER, EVENT, PROCEDURE, FUNCTION.
- The grammar for the mentioned objects is implemented with help of the rule view_or_trigger_or_sp_or_event. The grammar for all other object types is implemented directly in the create: rule. This makes the grammar non-symmetric for various object types, which is hard to read and understand.
- We'll add CREATE PACKAGE soon. It will require the DEFINER clause. In the current grammar, it will have to go to view_or_trigger_or_sp_or_event again, and make the things even more complex.
- LEX::create_view_mode, LEX::create_view_algorithm, LEX::create_view_suid are initialized for all objects described in view_or_trigger_or_sp_or_event. For non-VIEW objects this initialization is redundant.
| create_or_replace
{
Lex->create_info.set($1);
Lex->create_view_mode= ($1.or_replace() ? VIEW_CREATE_OR_REPLACE :
VIEW_CREATE_NEW);
Lex->create_view_algorithm= DTYPE_ALGORITHM_UNDEFINED;
Lex->create_view_suid= TRUE;
}
view_or_trigger_or_sp_or_event { }
- The grammar erroneously accepts these weird query:
ALTER VIEW IF NOT EXISTS v1 AS SELECT 1;
It's really senseless to ALTER something that NOT EXISTS.
The IF NOT EXISTS clause is accepted because both CREATE VIEW and ALTER VIEW grammar reuses the view_tail rule.
Under terms of this task we'll do the following:
- For stricter data type control: introduce a new enum instead of pre-processor constants:
enum enum_view_suid
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{
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VIEW_SUID_INVOKER= 0,
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VIEW_SUID_DEFINER= 1,
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VIEW_SUID_DEFAULT= 2
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};
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- Introduce a new class:
class Create_view_info: public Sql_alloc |
{
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public: |
LEX_CSTRING select; // The SELECT statement of CREATE VIEW |
enum enum_view_create_mode mode; |
uint16 algorithm;
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uint8 check;
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enum enum_view_suid suid; |
Create_view_info(enum_view_create_mode mode_arg,
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uint16 algorithm_arg,
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enum_view_suid suid_arg)
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:select(null_clex_str),
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mode(mode_arg),
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algorithm(algorithm_arg),
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check(VIEW_CHECK_NONE),
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suid(suid_arg)
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{ }
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};
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- Remove the same members from LEX and add a pointer to Create_view_info instead. Create_view_info will be allocated on THD memory root only for CREATE VIEW or ALTER VIEW queries.
- Reduce the amount of duplicate C++ code used in .yy files by adding new methods in LEX:
bool add_alter_view(THD *thd, uint16 algorithm, enum_view_suid suid,
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Table_ident *table_ident);
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bool add_create_view(THD *thd, DDL_options_st ddl,
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uint16 algorithm, enum_view_suid suid,
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Table_ident *table_ident);
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- In sql_yacc.yy: remove grammar rules view_or_trigger_or_sp_or_event, definer_tail, no_definer_tail, view_tail
- In sql_yacc.yy: add new grammar branches directly into the create: rules, for VIEW, TRIGGER, PROCEDURE, FUNCTION, EVENT.
Note, when we add the CREATE PACKAGE statement later (seeMDEV-10591), it will also be added directly to create:, together with its optional DEFINER clause.
- In sql_yacc.yy: fix the rules view_algorithm, view_suid, view_check_options to return values in $$, instead of setting thd->lex members directly. This is needed to pass these values to the new methods LEX::add_alter_view() and LEX::add_create_view().
- Do corresponding changes in sql_yacc_ora.yy.
Attachments
Issue Links
- blocks
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MDEV-10591 Oracle-style packages
- Closed