Contains value of an attribute. More...

#include <NdbRecAttr.hpp>

Public Member Functions
NdbRecAttr *	clone () const
	~NdbRecAttr ()
const NdbRecAttr *	next () const
Getting meta information
const NdbDictionary::Column *	getColumn () const
NdbDictionary::Column::Type	getType () const
Uint32	get_size_in_bytes () const
Getting stored value
int	isNULL () const
Int64	int64_value () const
Int32	int32_value () const
Int32	medium_value () const
short	short_value () const
char	char_value () const
Int8	int8_value () const
Uint64	u_64_value () const
Uint32	u_32_value () const
Uint32	u_medium_value () const
Uint16	u_short_value () const
Uint8	u_char_value () const
Uint8	u_8_value () const
float	float_value () const
double	double_value () const
Getting reference to stored value
char *	aRef () const

Friends
class	NdbOperation
class	NdbScanOperation
class	NdbIndexScanOperation
class	NdbEventOperationImpl
class	NdbReceiver
class	Ndb
class	NdbQueryOperationImpl
struct	Ndb_free_list_t< NdbRecAttr >
class NdbOut &	operator<< (class NdbOut &, const class AttributeS &)

Detailed Description

Contains value of an attribute.

NdbRecAttr objects are used to store the attribute value after retrieving the value from the NDB Cluster using the method NdbOperation::getValue. The objects are allocated by the NDB API. An example application program follows:

MyRecAttr = MyOperation->getValue("ATTR2", NULL);
if (MyRecAttr == NULL) goto error;
if (MyTransaction->execute(Commit) == -1) goto error;
ndbout << MyRecAttr->u_32_value();

For more examples, see ndbapi_simple.cpp.

Note: The NdbRecAttr object is instantiated with its value when NdbTransaction::execute is called. Before this, the value is undefined. (NdbRecAttr::isNULL can be used to check if the value is defined or not.) This means that an NdbRecAttr object only has valid information between the time of calling NdbTransaction::execute and the time of Ndb::closeTransaction. The value of the null indicator is -1 until the NdbTransaction::execute method have been called.

For simple types, there are methods which directly getting the value from the NdbRecAttr object.

To get a reference to the value, there are two methods: NdbRecAttr::aRef (memory is released by NDB API) and NdbRecAttr::getAttributeObject (memory must be released by application program). The two methods may return different pointers.

There are also methods to check attribute type, attribute size and array size. The method NdbRecAttr::arraySize returns the number of elements in the array (where each element is of size given by NdbRecAttr::attrSize). The NdbRecAttr::arraySize method is needed when reading variable-sized attributes.

Note: Variable-sized attributes are not yet supported.

Definition at line 74 of file NdbRecAttr.hpp.

Constructor & Destructor Documentation

NdbRecAttr::~NdbRecAttr ( )

Destructor

Note: You should only delete RecAttr-copies, i.e. objects that has been cloned.

Definition at line 32 of file NdbRecAttr.cpp.

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Member Function Documentation

char * NdbRecAttr::aRef ( ) const

inline

Get reference to attribute value.

Returns a char*-pointer to the value. The pointer is aligned appropriately for the data type. The memory is released when Ndb::closeTransaction is executed for the transaction which read the value.

Note: The memory is released by NDB API.; The pointer to the attribute value stored in an NdbRecAttr object (i.e. the pointer returned by aRef) is constant. This means that this method can be called anytime after NdbOperation::getValue has been called.

Returns: Pointer to attribute value.

Definition at line 423 of file NdbRecAttr.hpp.

char NdbRecAttr::char_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: Char value.

Definition at line 338 of file NdbRecAttr.hpp.

NdbRecAttr * NdbRecAttr::clone ( ) const

Make a copy of RecAttr object including all data.

Note: Copy needs to be deleted by application program.

Definition at line 113 of file NdbRecAttr.cpp.

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double NdbRecAttr::double_value ( ) const

Get value stored in NdbRecAttr object.

Returns: Double value.

Definition at line 218 of file NdbRecAttr.cpp.

float NdbRecAttr::float_value ( ) const

Get value stored in NdbRecAttr object.

Returns: Float value.

Definition at line 210 of file NdbRecAttr.cpp.

Uint32 NdbRecAttr::get_size_in_bytes ( ) const

inline

Get attribute (element) size in bytes.

Definition at line 104 of file NdbRecAttr.hpp.

NdbDictionary::Column::Type NdbRecAttr::getType ( ) const

inline

Get type of column

Returns: Data type of the column

Definition at line 312 of file NdbRecAttr.hpp.

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Int32 NdbRecAttr::int32_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: 32 bit int value.

Definition at line 324 of file NdbRecAttr.hpp.

Int64 NdbRecAttr::int64_value ( ) const

Get value stored in NdbRecAttr object.

Returns: 64 bit long value.

Definition at line 194 of file NdbRecAttr.cpp.

Int8 NdbRecAttr::int8_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: Int8 value.

Definition at line 345 of file NdbRecAttr.hpp.

int NdbRecAttr::isNULL ( ) const

inline

Check if attribute value is NULL.

Returns: -1 = Not defined (Failure or NdbTransaction::execute not yet called).
0 = Attribute value is defined, but not equal to NULL.
1 = Attribute value is defined and equal to NULL.

Definition at line 452 of file NdbRecAttr.hpp.

Int32 NdbRecAttr::medium_value ( ) const

Get value stored in NdbRecAttr object.

Returns: Medium value.

Definition at line 226 of file NdbRecAttr.cpp.

short NdbRecAttr::short_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: Short value.

Definition at line 331 of file NdbRecAttr.hpp.

Uint32 NdbRecAttr::u_32_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: 32 bit unsigned value.

Definition at line 352 of file NdbRecAttr.hpp.

Uint64 NdbRecAttr::u_64_value ( ) const

Get value stored in NdbRecAttr object.

Returns: 64 bit unsigned value.

Definition at line 202 of file NdbRecAttr.cpp.

Uint8 NdbRecAttr::u_8_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: Uint8 value.

Definition at line 373 of file NdbRecAttr.hpp.

Uint8 NdbRecAttr::u_char_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: Unsigned char value.

Definition at line 366 of file NdbRecAttr.hpp.

Uint32 NdbRecAttr::u_medium_value ( ) const

Get value stored in NdbRecAttr object.

Returns: Unsigned medium value.

Definition at line 232 of file NdbRecAttr.cpp.

Uint16 NdbRecAttr::u_short_value ( ) const

inline

Get value stored in NdbRecAttr object.

Returns: Unsigned short value.

Definition at line 359 of file NdbRecAttr.hpp.

Friends And Related Function Documentation

friend class Ndb

friend

Reciver(s)

Definition at line 82 of file NdbRecAttr.hpp.

friend class NdbOperation

friend

Sender(s)

Definition at line 77 of file NdbRecAttr.hpp.

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

storage/ndb/include/ndbapi/NdbRecAttr.hpp
storage/ndb/src/ndbapi/NdbRecAttr.cpp

Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation