Item_func_nullif Class Reference

Inheritance diagram for Item_func_nullif:

List of all members.

Public Member Functions
	Item_func_nullif (Item *a, Item *b)
double	val_real ()
longlong	val_int ()
String *	val_str (String *str)
my_decimal *	val_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 ()

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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.

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

• item_cmpfunc.h
• item_cmpfunc.cc