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Item_func_get_system_var Class Reference
Inheritance diagram for Item_func_get_system_var:
Item_var_func Item_func Item_result_field Item

List of all members.

Public Member Functions

 Item_func_get_system_var (sys_var *var_arg, enum_var_type var_type_arg, LEX_STRING *component_arg, const char *name_arg, size_t name_len_arg)
enum Functype functype () const
void update_null_value ()
void fix_length_and_dec ()
void print (String *str, enum_query_type query_type)
bool const_item () const
table_map used_tables () const
enum Item_result result_type () const
enum_field_types field_type () const
double val_real ()
longlong val_int ()
Stringval_str (String *)
my_decimalval_decimal (my_decimal *dec_buf)
const char * func_name () const
bool is_written_to_binlog ()
bool eq (const Item *item, bool binary_cmp) const
void cleanup ()

Member Function Documentation

bool Item_func_get_system_var::eq ( const Item item,
bool  binary_cmp 
) const [virtual]

This function is called when:

  • Comparing items in the WHERE clause (when doing where optimization)
  • When trying to find an ORDER BY/GROUP BY item in the SELECT part
  • When matching fields in multiple equality objects (Item_equal)

Reimplemented from Item_func.

Indicates whether this system variable is written to the binlog or not.

Variables are written to the binlog as part of "status_vars" in Query_log_event, as an Intvar_log_event, or a Rand_log_event.

true if the variable is written to the binlog, false otherwise.
void Item_func_get_system_var::print ( String str,
enum_query_type  query_type 
) [virtual]

This method is used for to:

  • to generate a view definition query (SELECT-statement);
  • to generate a SQL-query for EXPLAIN EXTENDED;
  • to generate a SQL-query to be shown in INFORMATION_SCHEMA;
  • debug.

For more information about view definition query, INFORMATION_SCHEMA query and why they should be generated from the Item-tree,

See also:

Reimplemented from Item_func.

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