os/persistentdata/persistentstorage/sql/SRC/Client/SqlStmtSession.h
author sl@SLION-WIN7.fritz.box
Fri, 15 Jun 2012 03:10:57 +0200
changeset 0 bde4ae8d615e
permissions -rw-r--r--
First public contribution.
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// Copyright (c) 2005-2010 Nokia Corporation and/or its subsidiary(-ies).
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// All rights reserved.
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// This component and the accompanying materials are made available
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// under the terms of "Eclipse Public License v1.0"
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// which accompanies this distribution, and is available
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// at the URL "http://www.eclipse.org/legal/epl-v10.html".
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//
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// Initial Contributors:
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// Nokia Corporation - initial contribution.
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//
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// Contributors:
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// NTT DOCOMO, INC - Fix for Bug 1915 "SQL server panics when using long column type strings"
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//
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// Description:
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//
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#ifndef __SQLSTMTSESSION_H__
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#define __SQLSTMTSESSION_H__
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#include <e32std.h>
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#include "SqlDbSession.h"		//RSqlDbSession
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#include "SqlBufFlat.h"			//RSqlBufFlat
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#include "IPCBuf.h"				//HIpcBuf
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/**
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RSqlStatementSession class is used for "prepare once execute many times" supplied to PrepareL() SQL 
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statement.
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RSqlStatementSession::PrepareL() must be called for preparing the SQL statement.
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If the SQL statement contains parameters, Bind() must be called before calling Next() or Exec() 
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to bind the parameter values.
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RSqlStatementSession class shall not be used for executing a set of SQL statements, separated with ";".
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PrepareL() will report this as a KErrArgument error.
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RSqlStatementSession class hides all details about the communication with the database server.
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No database specific header files should be seen or used outside the session class.
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Usage patterns:
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1) SQL statement which does not return a record set.
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@code
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	RSqlStatementSession sess;
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	TInt err = sess.Prepare(...);
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	...
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	RSqlBufFlat paramBuf;
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	<Initialize "paramBuf" object>;
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begin:
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	err = sess.Bind(paramBuf);
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	err = sess.Exec();
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	err = sess.Reset();
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	<Now a new set of parameter values can be prepared and the statement can be executed again - from the "begin" label>;
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	sess.Close();
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@endcode
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2) SQL statement which returns a record set.
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@code
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	RSqlStatementSession sess;
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	TInt err = sess.Prepare(...);
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	...
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	RSqlBufFlat paramBuf;
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	<Initialize "paramBuf" object>;
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	RSqlBufFlat columnBuf;
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	<Initialize "columnBuf" object. The element count must match the columns count>;
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begin:
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	err = sess.Bind(paramBuf);
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	while(sess.Next(columnBuf) == KSqlAtRow)
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		{
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		<process the record data - "columnBuf" set>;
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		}
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	err = sess.Reset();
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	<Now a new set of parameter values can be prepared and the statement can be executed again - from the "begin" label>;
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	sess.Close();
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@endcode
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@internalComponent
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*/
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NONSHARABLE_CLASS(RSqlStatementSession)
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	{
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public:	
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	inline RSqlStatementSession();
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	TInt Prepare(RSqlDbSession& aDbSession, const TDesC& aSqlStmt, TInt& aColumnCount, TInt& aParamCount);
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	TInt Prepare(RSqlDbSession& aDbSession, const TDesC8& aSqlStmt, TInt& aColumnCount, TInt& aParamCount);
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	void Close();
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	inline TInt Reset();
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	inline TInt Exec();
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	inline void Exec(TRequestStatus& aStatus);
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	inline TInt BindExec(const RSqlBufFlat& aParamBuf);
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	inline void BindExec(const RSqlBufFlat& aParamBuf, TRequestStatus& aStatus);
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	inline TInt Next(RSqlBufFlat& aColumnBuf);
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	TInt BindNext(const RSqlBufFlat& aParamBuf, RSqlBufFlat& aColumnBuf);
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	TInt GetNames(TSqlSrvFunction aFunction, RSqlBufFlat& aNameBuf);
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	inline TInt ReadColumnValue(TInt aColumnIndex, TDes8& aBuf);
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	inline MStreamBuf* ColumnSourceL(TInt aColumnIndex);
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	inline MStreamBuf* ParamSinkL(TSqlSrvFunction aFunction, TInt aParamIndex);
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	TInt GetDeclColumnTypes(RSqlBufFlat& aDeclColumnTypeBuf);	
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private:
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	TInt DoBindNext(TSqlSrvFunction aFunction, TIpcArgs& aIpcArgs, RSqlBufFlat& aColumnBuf);
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	TInt Retry(RSqlBufFlat& aBufFlat, TInt aSize, TSqlBufFlatType aWhat);
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	inline RSqlDbSession& DbSession() const;
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private:
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	TInt			iHandle;
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	RSqlDbSession*	iDbSession;
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	};
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#include "SqlStmtSession.inl"
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#endif//__SQLSTMTSESSION_H__