MySQL 8.0.40
Source Code Documentation
Sql_cmd_update Class Referencefinal

#include <sql_update.h>

Inheritance diagram for Sql_cmd_update:
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Public Member Functions

 Sql_cmd_update (bool multitable_arg, mem_root_deque< Item * > *update_values)
 
enum_sql_command sql_command_code () const override
 Return the command code for this statement. More...
 
bool is_single_table_plan () const override
 
- Public Member Functions inherited from Sql_cmd_dml
virtual bool is_data_change_stmt () const
 
bool prepare (THD *thd) override
 Command-specific resolving (doesn't include LEX::prepare()) More...
 
bool execute (THD *thd) override
 Execute a DML statement. More...
 
bool is_dml () const override
 
virtual bool may_use_cursor () const
 
Query_resultquery_result () const
 
void set_query_result (Query_result *result)
 Set query result object for this query statement. More...
 
void set_lazy_result ()
 Signal that root result object needs preparing in next execution. More...
 
- Public Member Functions inherited from Sql_cmd
bool needs_explicit_preparation () const
 
bool is_regular () const
 
bool is_prepared () const
 
virtual bool reprepare_on_execute_required () const
 Some SQL commands currently require re-preparation on re-execution of a prepared statement or stored procedure. More...
 
virtual void cleanup (THD *)
 Command-specific reinitialization before execution of prepared statement. More...
 
void set_owner (Prepared_statement *stmt)
 Set the owning prepared statement. More...
 
Prepared_statementowner () const
 Get the owning prepared statement. More...
 
void set_as_part_of_sp ()
 Mark statement as part of procedure. More...
 
bool is_part_of_sp () const
 
virtual const MYSQL_LEX_CSTRINGeligible_secondary_storage_engine () const
 Is this statement of a type and on a form that makes it eligible for execution in a secondary storage engine? More...
 
void disable_secondary_storage_engine ()
 Disable use of secondary storage engines in this statement. More...
 
bool secondary_storage_engine_disabled () const
 Has use of secondary storage engines been disabled for this statement? More...
 
void use_secondary_storage_engine (const handlerton *hton)
 Mark the current statement as using a secondary storage engine. More...
 
bool using_secondary_storage_engine () const
 Is this statement using a secondary storage engine? More...
 
const handlertonsecondary_engine () const
 Get the handlerton of the secondary engine that is used for executing this statement, or nullptr if a secondary engine is not used. More...
 
void set_optional_transform_prepared (bool value)
 
bool is_optional_transform_prepared ()
 

Public Attributes

mem_root_deque< Item * > original_fields
 The original list of fields to update, used for privilege checking. More...
 
mem_root_deque< Item * > * update_value_list
 The values used to update fields. More...
 

Protected Member Functions

bool precheck (THD *thd) override
 Perform a precheck of table privileges for the specific operation. More...
 
bool check_privileges (THD *thd) override
 Check privileges on a prepared statement, called at start of execution of the statement. More...
 
bool prepare_inner (THD *thd) override
 Perform the command-specific parts of DML command preparation, to be called from prepare() More...
 
bool execute_inner (THD *thd) override
 The inner parts of query optimization and execution. More...
 
- Protected Member Functions inherited from Sql_cmd_dml
 Sql_cmd_dml ()
 
bool is_empty_query () const
 
void set_empty_query ()
 Set statement as returning no data. More...
 
bool check_all_table_privileges (THD *thd)
 Read and check privileges for all tables in a DML statement. More...
 
virtual bool restore_cmd_properties (THD *thd)
 Restore command properties before execution. More...
 
virtual bool save_cmd_properties (THD *thd)
 Save command properties, such as prepared query details and table props. More...
 
const MYSQL_LEX_CSTRINGget_eligible_secondary_engine () const
 Helper function that checks if the command is eligible for secondary engine and if that's true returns the name of that eligible secondary storage engine. More...
 
- Protected Member Functions inherited from Sql_cmd
 Sql_cmd ()
 
virtual ~Sql_cmd ()
 
void set_prepared ()
 Set this statement as prepared. More...
 

Private Member Functions

bool update_single_table (THD *thd)
 Perform an update to a set of rows in a single table. More...
 
bool accept (THD *thd, Select_lex_visitor *visitor) override
 
bool make_base_table_fields (THD *thd, mem_root_deque< Item * > *items)
 Convert list of fields to update to base table fields. More...
 

Private Attributes

bool multitable
 
table_map tables_for_update {0}
 Bitmap of all tables which are to be updated. More...
 

Additional Inherited Members

- Protected Attributes inherited from Sql_cmd_dml
LEXlex
 Pointer to LEX for this statement. More...
 
Query_resultresult
 Pointer to object for handling of the result. More...
 
bool m_empty_query
 True if query will produce no rows. More...
 
bool m_lazy_result
 True: prepare query result on next execution. More...
 

Constructor & Destructor Documentation

◆ Sql_cmd_update()

Sql_cmd_update::Sql_cmd_update ( bool  multitable_arg,
mem_root_deque< Item * > *  update_values 
)
inline

Member Function Documentation

◆ accept()

bool Sql_cmd_update::accept ( THD thd,
Select_lex_visitor visitor 
)
overrideprivatevirtual

Reimplemented from Sql_cmd.

◆ check_privileges()

bool Sql_cmd_update::check_privileges ( THD thd)
overrideprotectedvirtual

Check privileges on a prepared statement, called at start of execution of the statement.

Check that user has all relevant privileges to the statement, ie. INSERT privilege for columns inserted into, UPDATE privilege for columns that are updated, DELETE privilege for tables that are deleted from, SELECT privilege for columns that are referenced, etc.

Parameters
thdthread handler
Returns
false if success, true if false

Implements Sql_cmd_dml.

◆ execute_inner()

bool Sql_cmd_update::execute_inner ( THD thd)
overrideprotectedvirtual

The inner parts of query optimization and execution.

Execute a DML statement.

Single-table DML operations needs to reimplement this.

Parameters
thdThread handler
Returns
false on success, true on error

This is the default implementation for a DML statement and uses a nested-loop join processor per outer-most query block. The implementation is split in two: One for query expressions containing a single query block and one for query expressions containing multiple query blocks combined with UNION.

Reimplemented from Sql_cmd_dml.

◆ is_single_table_plan()

bool Sql_cmd_update::is_single_table_plan ( ) const
inlineoverridevirtual
Returns
true if implemented as single table plan, DML statement only

Reimplemented from Sql_cmd_dml.

◆ make_base_table_fields()

bool Sql_cmd_update::make_base_table_fields ( THD thd,
mem_root_deque< Item * > *  items 
)
private

Convert list of fields to update to base table fields.

Check that all fields are base table columns.

Replace columns from views with base table columns.

Parameters
thdthread handler
itemsItems for check
Returns
false if success, true if error (OOM)

◆ precheck()

bool Sql_cmd_update::precheck ( THD thd)
overrideprotectedvirtual

Perform a precheck of table privileges for the specific operation.

Check that user has some relevant privileges for all tables involved in the statement, e.g. SELECT privileges for tables selected from, INSERT privileges for tables inserted into, etc. This function will also populate Table_ref::grant with all privileges the user has for each table, which is later used during checking of column privileges. Note that at preparation time, views are not expanded yet. Privilege checking is thus rudimentary and must be complemented with later calls to Query_block::check_view_privileges(). The reason to call this function at such an early stage is to be able to quickly reject statements for which the user obviously has insufficient privileges. This function is called before preparing the statement. The function must also be complemented with proper privilege checks for all involved columns (e.g. check_column_grant_*).

See also
also the function comment of Query_block::prepare(). During execution of a prepared statement, call check_privileges() instead.
Parameters
thdthread handler
Returns
false if success, true if false

Implements Sql_cmd_dml.

◆ prepare_inner()

bool Sql_cmd_update::prepare_inner ( THD thd)
overrideprotectedvirtual

Perform the command-specific parts of DML command preparation, to be called from prepare()

Parameters
thdthe current thread
Returns
false if success, true if error

Implements Sql_cmd_dml.

◆ sql_command_code()

enum_sql_command Sql_cmd_update::sql_command_code ( ) const
inlineoverridevirtual

Return the command code for this statement.

Implements Sql_cmd.

◆ update_single_table()

bool Sql_cmd_update::update_single_table ( THD thd)
private

Perform an update to a set of rows in a single table.

Parameters
thdThread handler
Returns
false if success, true if error

< Flag for fatal errors

read_removal is only used by NDB storage engine

Member Data Documentation

◆ multitable

bool Sql_cmd_update::multitable
private

◆ original_fields

mem_root_deque<Item *> Sql_cmd_update::original_fields

The original list of fields to update, used for privilege checking.

◆ tables_for_update

table_map Sql_cmd_update::tables_for_update {0}
private

Bitmap of all tables which are to be updated.

◆ update_value_list

mem_root_deque<Item *>* Sql_cmd_update::update_value_list

The values used to update fields.


The documentation for this class was generated from the following files: