Object identifying the SQL data type LOB (CLOB, NCLOB and BLOB) More...

#include <ocilib.hpp>

Inherits ocilib::HandleHolder< OCI_Lob *>.

Public Member Functions
	Lob ()
	Create an empty null Lob instance.

	Lob (const Connection &connection)
	Parametrized constructor. More...

T	Read (unsigned int length)
	Read a portion of a lob. More...

unsigned int	Write (const T &content)
	Write the given content at the current position within the lob. More...

unsigned int	Append (const T &content)
	Append the given content to the lob. More...

void	Append (const Lob &other)
	Append the given lob content to the lob. More...

bool	Seek (SeekMode seekMode, big_uint offset)
	Move the current position within the lob for read/write operations. More...

LobType	GetType () const
	return the type of lob

big_uint	GetOffset () const
	Returns the current R/W offset within the lob.

big_uint	GetLength () const
	Returns the number of characters or bytes contained in the lob.

big_uint	GetMaxSize () const
	Returns the lob maximum possible size.

big_uint	GetChunkSize () const
	Returns the current lob chunk size. More...

Connection	GetConnection () const
	Return the lob parent connection.

void	Truncate (big_uint length)
	Truncate the lob to a shorter length. More...

big_uint	Erase (big_uint offset, big_uint length)
	Erase a portion of the lob at a given position. More...

void	Copy (Lob &dest, big_uint offset, big_uint offsetDest, big_uint length) const
	Copy the given portion of the lob content to another one. More...

bool	IsTemporary () const
	Check if the given lob is a temporary lob.

bool	IsRemote () const
	Check if the given lob is a remote lob.

void	Open (OpenMode mode)
	Open explicitly a Lob. More...

void	Flush ()
	Flush the lob content to the server (if applicable)

void	Close ()
	Close explicitly a Lob. More...

void	EnableBuffering (bool value)
	Enable / disable buffering mode on the given lob object. More...

Lob	Clone () const
	Clone the current instance to a new one performing deep copy.

Lob &	operator+= (const Lob &other)
	Appending the given lob content to the current lob content.

bool	operator== (const Lob &other) const
	Indicates if the current lob value is equal to the given lob value.

bool	operator!= (const Lob &other) const
	Indicates if the current lob value is not equal the given lob value.

Detailed Description

template<class T, int U>
class ocilib::Lob< T, U >

Object identifying the SQL data type LOB (CLOB, NCLOB and BLOB)

This class wraps the OCILIB object handle OCI_Lob and its related methods

Definition at line 4173 of file ocilib.hpp.

Constructor & Destructor Documentation

◆ Lob()

template<class T , int U>

ocilib::Lob< T, U >::Lob ( const Connection & connection )

Parametrized constructor.

Parameters

connection - Parent connection

Note: the lob object must not be accessed anymore once the parent connection object gets out of scope

Definition at line 3079 of file ocilib_impl.hpp.

References ocilib::Check(), ocilib::Environment::GetCharMaxSize(), ocilib::Lob< T, U >::Lob(), OCI_LobCreate(), OCI_LobFree(), OCI_LobRead2(), and ocilib::Lob< T, U >::Read().

Member Function Documentation

◆ Read()

template<class T, int U>

T ocilib::Lob< T, U >::Read ( unsigned int length )

Read a portion of a lob.

Parameters

length - Maximum number of characters or bytes to read

Returns: The content read from the lob

Referenced by ocilib::Lob< T, U >::Lob().

◆ Write()

template<class T , int U>

unsigned int ocilib::Lob< T, U >::Write ( const T & content )

Write the given content at the current position within the lob.

Parameters

content - content to write

Returns: Number of character or bytes written into the lob

Definition at line 3134 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobWrite2().

◆ Append() [1/2]

template<class T , int U>

unsigned int ocilib::Lob< T, U >::Append ( const T & content )

Append the given content to the lob.

Parameters

content - content to write

Returns: Number of character or bytes written into the lob

Definition at line 3160 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobAppend().

◆ Append() [2/2]

template<class T , int U>

void ocilib::Lob< T, U >::Append ( const Lob< T, U > & other )

Append the given lob content to the lob.

Parameters

other - source lob

Definition at line 3154 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobAppendLob().

◆ Seek()

template<class T , int U>

bool ocilib::Lob< T, U >::Seek	(	SeekMode	seekMode,
		big_uint	offset
	)

Move the current position within the lob for read/write operations.

Parameters

seekMode	- Seek mode
offset	- offset from current position

Note: Positions start at 0.

Returns: true on success otherwise false

Definition at line 3173 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobSeek().

◆ GetChunkSize()

template<class T , int U>

big_uint ocilib::Lob< T, U >::GetChunkSize ( ) const

Returns the current lob chunk size.

Note: This chunk size corresponds to the chunk size used by the LOB data layer when accessing and modifying the LOB value. According to Oracle documentation, performance will be improved if the application issues read or write requests using a multiple of this chunk size

Definition at line 3219 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobGetChunkSize().

◆ Truncate()

template<class T , int U>

void ocilib::Lob< T, U >::Truncate ( big_uint length )

Truncate the lob to a shorter length.

Parameters

length - New length in characters or bytes

Definition at line 3231 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobTruncate().

◆ Erase()

template<class T , int U>

big_uint ocilib::Lob< T, U >::Erase	(	big_uint	offset,
		big_uint	length
	)

Erase a portion of the lob at a given position.

Parameters

offset	- Absolute position in source lob
length	- Number of bytes or characters to erase

Note: Absolute position starts at 0. Erasing means that space or null values overwrite the existing LOB value.

Returns: Number of characters or bytes erased

Definition at line 3237 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobErase().

◆ Copy()

template<class T , int U>

void ocilib::Lob< T, U >::Copy	(	Lob< T, U > &	dest,
		big_uint	offset,
		big_uint	offsetDest,
		big_uint	length
	)		const

Copy the given portion of the lob content to another one.

Parameters

dest	- Destination lob
offset	- Absolute position in the lob
offsetDest	- Absolute position in the destination lob
length	- Number of characters or bytes to copy

Note: Absolute position starts at 0.

Definition at line 3243 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobCopy().

◆ Open()

template<class T , int U>

void ocilib::Lob< T, U >::Open ( OpenMode mode )

Open explicitly a Lob.

Parameters

mode	- open mode

Note

A call to Open() is not necessary to manipulate a Lob.
If a lob hasn't been opened explicitly, triggers are fired and indexes updated at every read/write/append operation

Definition at line 3261 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobOpen().

◆ Close()

template<class T , int U>

void ocilib::Lob< T, U >::Close ( )

Close explicitly a Lob.

Note

A call to Close() is not necessary to manipulate a Lob.

Definition at line 3273 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobClose().

◆ EnableBuffering()

template<class T , int U>

void ocilib::Lob< T, U >::EnableBuffering ( bool value )

Enable / disable buffering mode on the given lob object.

Parameters

value - Enable/disable buffering mode

Note: Oracle "LOB Buffering Subsystem" allows client applications to speedup read/write of small buffers on Lobs Objects. Check Oracle Documentation for more details on "LOB Buffering Subsystem". This reduces the number of network round trips and LOB versions, thereby improving LOB performance significantly.

Warning: According to Oracle documentation the following operations are not permitted on Lobs when buffering is on : Copy(), Append(), Erase(), GetLength(), Truncate()

Definition at line 3279 of file ocilib_impl.hpp.

References ocilib::Check(), and OCI_LobEnableBuffering().

Public Member Functions

Detailed Description

template<class T, int U> class ocilib::Lob< T, U >

Constructor & Destructor Documentation

◆ Lob()

Member Function Documentation

◆ Read()

◆ Write()

◆ Append() [1/2]

◆ Append() [2/2]

◆ Seek()

◆ GetChunkSize()

◆ Truncate()

◆ Erase()

◆ Copy()

◆ Open()

◆ Close()

◆ EnableBuffering()

template<class T, int U>
class ocilib::Lob< T, U >