RSqlParamWriteStream Class Reference

#include <sqldb.h>

Link against: sqldb.lib

class RSqlParamWriteStream : public RWriteStream

Inherits from

RSqlParamWriteStream

Public Member Functions
IMPORT_C TInt	BindBinary(RSqlStatement &, TInt)
IMPORT_C void	BindBinaryL(RSqlStatement &, TInt)
IMPORT_C TInt	BindText(RSqlStatement &, TInt)
IMPORT_C void	BindTextL(RSqlStatement &, TInt)

Inherited Functions
	RWriteStream::Attach(MStreamBuf *)
	RWriteStream::Close()
	RWriteStream::CommitL()
	RWriteStream::Detach()
	RWriteStream::Pop()
	RWriteStream::PushL()
	RWriteStream::RWriteStream()
	RWriteStream::RWriteStream(MStreamBuf *)
	RWriteStream::RWriteStream(const MExternalizer< TStreamRef > &)
	RWriteStream::Release()
	RWriteStream::Sink()
	RWriteStream::WriteInt16L(TInt)
	RWriteStream::WriteInt32L(TInt32)
	RWriteStream::WriteInt8L(TInt)
	RWriteStream::WriteL(RReadStream &)
	RWriteStream::WriteL(RReadStream &,TInt)
	RWriteStream::WriteL(const TDesC16 &)
	RWriteStream::WriteL(const TDesC16 &,TInt)
	RWriteStream::WriteL(const TDesC8 &)
	RWriteStream::WriteL(const TDesC8 &,TInt)
	RWriteStream::WriteL(const TUint16 *,TInt)
	RWriteStream::WriteL(const TUint8 *,TInt)
	RWriteStream::WriteReal32L(TReal)
	RWriteStream::WriteReal64L(TReal64)
	RWriteStream::WriteUint16L(TUint)
	RWriteStream::WriteUint32L(TUint32)
	RWriteStream::WriteUint8L(TUint)

Detailed Description

The write stream interface.

The class is used to set binary data or text data into a parameter. This is a also known as binding a parameter.

The class derives from RWriteStream, which means that all RWriteStream public member functions and predefined stream operators << can be used to deal with the parameter data.

If the blob or text data is over 2Mb in size then it is recommended that the RSqlBlobWriteStream or TSqlBlob class is used instead. These classes provide a more RAM-efficient way of writing large amounts of blob or text data to a database.

The following two cases are typical:

CASE 1 - binding a large binary parameter.

RSqlDatabase db;
<open/create "db" object>;
RSqlStatement stmt;
<prepare "stmt" object>;//The SQL statement references large binary parameter
RSqlParamWriteStream paramStream;
CleanupClosePushL(paramStream);
User::LeaveIfError(paramStream.BindBinary(stmt, <parameter_number>));
//Write out the parameter data
paramStream.WriteL(..);
paramStream << <data>;
...
//Commit the stream
paramStream.CommitL();
//Continue with the statement processing issuing Next() or Exec().
TInt rc = stmt.Next();//rc = stmt.Exec()
//Close the stream
CleanupStack::PopAndDestroy(&paramStream);

CASE 2 - binding a large text parameter.

RSqlDatabase db;
<open/create "db" object>;
RSqlStatement stmt;
<prepare "stmt" object>;//The SQL statement references large text parameter
RSqlParamWriteStream paramStream;
CleanupClosePushL(paramStream);
User::LeaveIfError(paramStream.BindText(stmt, <parameter_number>));
//Write out the parameter data
paramStream.WriteL(..);
paramStream << <data>;
...
//Commit the stream
paramStream.CommitL();
//Continue with the statement processing issuing Next() or Exec().
TInt rc = stmt.Next();//rc = stmt.Exec()
//Close the stream
CleanupStack::PopAndDestroy(&paramStream);

Member Function Documentation

BindBinary ( RSqlStatement &, TInt )

IMPORT_C TInt	BindBinary	(	RSqlStatement &	aStmt,
			TInt	aParameterIndex
		)

Gives access to parameter data as a stream of bytes.

NB You need to close the stream after the execution of the statement operation for which the parameter is set (RSqlStatement::Next() or RSqlStatement::Exec()).

capability: None

Parameter	Description
aStmt	The RSqlStatement object to which the referred parameter belongs.
aParameterIndex	The index value identifying the parameter; this is 0 for the first parameter.

Returns: KErrNone, the binary parameter data stream has been opened successfully; KErrNoMemory, an out of memory condition occurred. Note that database specific errors categorised as ESqlDbError, and other system-wide error codes may also be returned.

BindBinaryL ( RSqlStatement &, TInt )

IMPORT_C void	BindBinaryL	(	RSqlStatement &	aStmt,
			TInt	aParameterIndex
		)

Gives access to parameter data as a stream of bytes.

NB You need to close the stream after the execution of the statement operation for which the parameter is set (RSqlStatement::Next() or RSqlStatement::Exec()).

leave: KErrNoMemory, an out of memory condition occurred. Note that database specific errors categorised as ESqlDbError, and other system-wide error codes may also be returned.

capability: None

Parameter	Description
aStmt	The RSqlStatement object to which the referred parameter belongs.
aParameterIndex	The index value identifying the parameter; this is 0 for the first parameter.

BindText ( RSqlStatement &, TInt )

IMPORT_C TInt	BindText	(	RSqlStatement &	aStmt,
			TInt	aParameterIndex
		)

Gives access to parameter data as a stream of characters.

NB You need to close the stream after the execution of the statement operation for which the parameter is set (RSqlStatement::Next() or RSqlStatement::Exec()).

capability: None

Parameter	Description
aStmt	The RSqlStatement object to which the referred parameter belongs.
aParameterIndex	The index value identifying the parameter; this is 0 for the first parameter.

BindTextL ( RSqlStatement &, TInt )

IMPORT_C void	BindTextL	(	RSqlStatement &	aStmt,
			TInt	aParameterIndex
		)

Gives access to parameter data as a stream of characters.

NB You need to close the stream after the execution of the statement operation for which the parameter is set (RSqlStatement::Next() or RSqlStatement::Exec()).

leave: KErrNoMemory, an out of memory condition occurred. Note that database specific errors categorised as ESqlDbError, and other system-wide error codes may also be returned.

capability: None

Parameter	Description
aStmt	The RSqlStatement object to which the referred parameter belongs.
aParameterIndex	The index value identifying the parameter; this is 0 for the first parameter.