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Item_func_nullif Class Reference
Inheritance diagram for Item_func_nullif:
Item_bool_func2 Item_bool_func Item_int_func Item_func Item_result_field Item

List of all members.

Public Member Functions

 Item_func_nullif (Item *a, Item *b)
double val_real ()
longlong val_int ()
Stringval_str (String *str)
my_decimalval_decimal (my_decimal *)
enum Item_result result_type () const
void fix_length_and_dec ()
uint decimal_precision () const
const char * func_name () const
virtual void print (String *str, enum_query_type query_type)
table_map not_null_tables () const
bool is_null ()

Member Function Documentation

virtual void Item_func_nullif::print ( String str,
enum_query_type  query_type 
) [inline, 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:
mysql_register_view().

Reimplemented from Item_bool_func2.

double Item_func_nullif::val_real ( void  ) [virtual]
Note:
Note that we have to evaluate the first argument twice as the compare may have been done with a different type than return value
Returns:
NULL if arguments are equal
the first argument if not equal

Reimplemented from Item_int_func.


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