ExecutionContext::SystemVariables Class Reference

system-variables as returned by the server. More...

#include <sql_exec_context.h>

Public Types
using	key_type = std::string
using	value_type = Value
using	iterator = std::map< key_type, value_type >::iterator
using	const_iterator = std::map< key_type, value_type >::const_iterator

Public Member Functions
void	set (key_type k, value_type v)
	set k to v. More...
std::optional< value_type >	find (const key_type &k) const
	find 'k' in sytem-vars. More...
value_type	get (const key_type &k) const
	get 'k' from system-vars. More...
iterator	begin ()
const_iterator	begin () const
iterator	end ()
const_iterator	end () const
bool	empty () const
	check if their is a no system-var. More...

Private Attributes
std::map< key_type, value_type >	vars_

Detailed Description

system-variables as returned by the server.

can be queried from the server with:

• SELECT @SESSION.{k}
• SELECT @LOCAL.{k}

can be set on the server with:

• SET k = v;
• SET @SESSION.k = v;
• SET @LOCAL.k = v;
• SET SESSION k = v;
• SET LOCAL k = v;

changes to system-vars on the server are returned via the sesssion-tracker for system-variables.

Member Typedef Documentation

const_iterator

using ExecutionContext::SystemVariables::const_iterator = std::map<key_type, value_type>::const_iterator

iterator

using ExecutionContext::SystemVariables::iterator = std::map<key_type, value_type>::iterator

key_type

using ExecutionContext::SystemVariables::key_type = std::string

value_type

using ExecutionContext::SystemVariables::value_type = Value

Member Function Documentation

begin() [1/2]

iterator ExecutionContext::SystemVariables::begin ( )

inline

begin() [2/2]

const_iterator ExecutionContext::SystemVariables::begin ( ) const

inline

empty()

bool ExecutionContext::SystemVariables::empty ( ) const

inline

check if their is a no system-var.

end() [1/2]

iterator ExecutionContext::SystemVariables::end ( )

inline

end() [2/2]

const_iterator ExecutionContext::SystemVariables::end ( ) const

inline

find()

std::optional< value_type > ExecutionContext::SystemVariables::find ( const key_type &  k ) const

inline

find 'k' in sytem-vars.

Parameters

k

key

if 'k' does not exist in system-vars, a NULL-like value is returned. otherwise return the value for the system-var referenced by 'k'

Returns

std::nullopt if key is not found, the found value otherwise.

get()

value_type ExecutionContext::SystemVariables::get ( const key_type &  k ) const

inline

get 'k' from system-vars.

Parameters

k

key

if 'k' does not exist in system-vars, a NULL-like value is returned. otherwise return the value for the system-var referenced by 'k' which may be NULL-like or a string.

Returns

std::nullopt if key is not found or value is NULL-like, the found value otherwise

set()

void ExecutionContext::SystemVariables::set ( key_type  k, value_type  v  )

inline

set k to v.

if k doesn't exist in the system-vars yet, it gets inserted.

Member Data Documentation

vars_

std::map<key_type, value_type> ExecutionContext::SystemVariables::vars_

private

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

• router/src/routing/src/sql_exec_context.h