MySQL 8.0.32
Source Code Documentation
Query_result_null Class Reference

A query result handler that outputs nothing. More...

Inheritance diagram for Query_result_null:
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Public Member Functions

 Query_result_null ()
 
uint field_count (const mem_root_deque< Item * > &) const override
 
bool send_result_set_metadata (THD *, const mem_root_deque< Item * > &, uint) override
 
bool send_data (THD *thd, const mem_root_deque< Item * > &items) override
 
bool send_eof (THD *) override
 
- Public Member Functions inherited from Query_result_interceptor
 Query_result_interceptor ()
 
uint field_count (const mem_root_deque< Item * > &) const override
 
bool send_result_set_metadata (THD *, const mem_root_deque< Item * > &, uint) override
 
bool is_interceptor () const final
 Checks if this Query_result intercepts and transforms the result set. More...
 
- Public Member Functions inherited from Query_result
 Query_result ()
 
virtual ~Query_result ()=default
 
virtual bool needs_file_privilege () const
 
virtual bool change_query_result (THD *, Query_result *)
 Change wrapped Query_result. More...
 
virtual bool need_explain_interceptor () const
 
virtual bool prepare (THD *, const mem_root_deque< Item * > &, Query_expression *u)
 Perform preparation specific to the query expression or DML statement. More...
 
virtual bool start_execution (THD *)
 Prepare for execution of the query expression or DML statement. More...
 
virtual bool create_table_for_query_block (THD *)
 Create table, only needed to support CREATE TABLE ... SELECT. More...
 
virtual bool check_supports_cursor () const
 Check if this query result set supports cursors. More...
 
virtual void abort_result_set (THD *)
 
virtual bool reset ()
 Cleanup after one execution of the unit, to be ready for a next execution inside the same statement. More...
 
virtual void cleanup ()
 Cleanup after this execution. More...
 
virtual void set_limit (ha_rows)
 Only overridden (and non-empty) for Query_result_union, q.v. More...
 
virtual Server_side_cursorcursor () const
 

Private Attributes

String m_str
 

Additional Inherited Members

- Public Attributes inherited from Query_result
ha_rows estimated_rowcount
 Number of records estimated in this result. More...
 
double estimated_cost
 Cost to execute the subquery which produces this result. More...
 
- Protected Attributes inherited from Query_result
Query_expressionunit
 

Detailed Description

A query result handler that outputs nothing.

It is used during EXPLAIN ANALYZE, to ignore the output of the query when it's being run.

Constructor & Destructor Documentation

◆ Query_result_null()

Query_result_null::Query_result_null ( )
inline

Member Function Documentation

◆ field_count()

uint Query_result_null::field_count ( const mem_root_deque< Item * > &  ) const
inlineoverridevirtual

Reimplemented from Query_result.

◆ send_data()

bool Query_result_null::send_data ( THD thd,
const mem_root_deque< Item * > &  items 
)
inlineoverridevirtual

Implements Query_result.

◆ send_eof()

bool Query_result_null::send_eof ( THD )
inlineoverridevirtual

Implements Query_result.

◆ send_result_set_metadata()

bool Query_result_null::send_result_set_metadata ( THD ,
const mem_root_deque< Item * > &  ,
uint   
)
inlineoverridevirtual

Implements Query_result.

Member Data Documentation

◆ m_str

String Query_result_null::m_str
private

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