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examples/SysLibs/SqlExample/sqlexample.cpp

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// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// This example program demonstrates the use of SQL APIs. 
// The code demonstrates how to create non secure and secure databases on 
// the writable drive and perform basic operations on the databases.
//



#include "sqlexample.h"
#include <e32cons.h>
#include <sqldb.h>

_LIT(KTitle, "SQL example");
_LIT(KTextPressAKey, "\n\nPress any key to step through the example\n");
_LIT(KExit,"Press any key to exit the application ");
_LIT(KPressAKey,"Press any key to continue \n");
_LIT(KNonSecure,"\nCreating a non secure database \n");
_LIT(KSecure,"\nCreating a secure database \n");
_LIT(KOpen,"Opening  the secure database \n");
_LIT(KDelete,"Deleting the database(s)\n");
_LIT(KClose,"Closing the database(s)\n");
_LIT(KCopyNonSec,"\nCopying a non secure database to another non secure one \n");
_LIT(KCopySecure,"\nCopying a secure database to another secure database \n");                                    
_LIT(KAttach,"\nOpen a secure database and attach another secure database\n");
_LIT(KCreateTable,"\nCreating a table\n");
_LIT(KInsert,"Inserting records into the table\n");
_LIT(KPrepare,"Preparing a query\n");
_LIT(KExecute,"Executing a query\n");

// Names of the databases created, operated upon and later deleted.
_LIT(KDbName, "\\Example_db.db");
_LIT(KAnotherDbName, "\\Example_Anotherdb.db");
_LIT(KSecureDb1, "[E80000AF]db1.db");
_LIT(KSecureDb2, "[E80000AF]db2.db");
_LIT(KDatabase, "\\Sqlscalarfullselect.db");

// Security policies used
const TSecurityPolicy KPolicy1(ECapabilityReadUserData, ECapabilityNetworkControl,  ECapabilityWriteUserData);
const TSecurityPolicy KPolicy2(ECapabilityReadUserData);

CSqlExample* CSqlExample::NewLC()
        {
        CSqlExample* rep = new(ELeave) CSqlExample();
        CleanupStack::PushL(rep);
        rep->ConstructL();
        return rep;
        }
        
CSqlExample::CSqlExample()
        {
        }       

void CSqlExample::ConstructL()
        {
        iConsole = Console::NewL(KTitle,TSize(KConsFullScreen,KConsFullScreen));
        iConsole->Printf ( KTextPressAKey );
        iConsole->Getch ();
        }

CSqlExample::~CSqlExample()
        {
        iConsole->Printf(KExit);
        iConsole->Getch();
        
        delete iConsole;
        }
        
void CSqlExample::CreateNonSecureDBL()
        {
        TBuf<200> buffer;
        RSqlDatabase db;
                
        // Create non-secure database
        iConsole->Printf(KNonSecure);
        TInt error;
        TRAP(error,db.Create(KDbName););

        _LIT(KTable,"CREATE TABLE A1(F1 INTEGER, F2 INTEGER)");
        User::LeaveIfError(error = db.Exec(KTable));

        db.Close();
        iConsole->Printf(KClose);
        iConsole->Printf(KPressAKey);
        iConsole->Getch();
        }
        
void CSqlExample::CreateAndOpenSecureDBL()
        {
        RSqlDatabase db;
        RSqlSecurityPolicy securityPolicy;
        
        User::LeaveIfError(securityPolicy.Create(TSecurityPolicy(TSecurityPolicy::EAlwaysPass)));
        User::LeaveIfError(securityPolicy.SetDbPolicy(RSqlSecurityPolicy::EWritePolicy, KPolicy1));
                
        iConsole->Printf(KSecure);
        User::LeaveIfError(db.Create(KSecureDb1, securityPolicy));
                
        securityPolicy.Close(); 
        
        // Check that the database security policy matches the policy used 
        //when the database was created.
        User::LeaveIfError(db.GetSecurityPolicy(securityPolicy));
        
        _LIT(KSecureCreate,"CREATE TABLE secure(int_fld integer, null_int_fld integer default null)");  
        User::LeaveIfError(db.Exec(KSecureCreate));

        // Attempt to write to the secure database
        _LIT(KSecureInsert,"INSERT INTO secure(int_fld) values(200)");
        User::LeaveIfError(db.Exec(KSecureInsert));
        db.Close();
        
        iConsole->Printf(KOpen);
        // Open the secure database     
        User::LeaveIfError(db.Open(KSecureDb1));
        
        db.Close();
        iConsole->Printf(KClose);
        iConsole->Printf(KPressAKey);
        iConsole->Getch();
        securityPolicy.Close();

        }
        
void CSqlExample::CopyDatabaseL()
        {
        RSqlDatabase db;        
        
        // Copy non-secure to non-secure database
        iConsole->Printf(KCopyNonSec);  
        User::LeaveIfError(RSqlDatabase::Copy(KDbName, KAnotherDbName));
        
        // Delete the source database
        iConsole->Printf(KDelete);
        User::LeaveIfError(RSqlDatabase::Delete(KAnotherDbName));

        // Create another secure database with a different security policy,
        // KSecureDb1 is already created with KPolicy1.
        RSqlSecurityPolicy securityPolicy;
        User::LeaveIfError(securityPolicy.Create(TSecurityPolicy(TSecurityPolicy::EAlwaysPass)));
        
        User::LeaveIfError(securityPolicy.SetDbPolicy(RSqlSecurityPolicy::EWritePolicy, KPolicy2));
                
        User::LeaveIfError(db.Create(KSecureDb2, securityPolicy));
        
        User::LeaveIfError(db.GetSecurityPolicy(securityPolicy));
        db.Close();
        
        // Copy secure to secure database. The application is the database owner.
        iConsole->Printf(KCopySecure);
        User::LeaveIfError(RSqlDatabase::Copy(KSecureDb1, KSecureDb2));
        
        // Delete the source database
        iConsole->Printf(KDelete);
        User::LeaveIfError(RSqlDatabase::Delete(KSecureDb1));

        iConsole->Printf(KPressAKey);
        iConsole->Getch();
        securityPolicy.Close(); 
        db.Close();

        }
        
void CSqlExample::AttachDatabasesL()
        {
        RSqlDatabase db;
        RSqlSecurityPolicy securityPolicy;

        _LIT(KAttachDb2, "Db2");
        
        User::LeaveIfError(db.Open(KSecureDb2));
        iConsole->Printf(KAttach);
        
        User::LeaveIfError(db.Attach(KDbName, KAttachDb2));
        
        // Attempt to write to the attached non secure database
        _LIT(KTabInsert,"INSERT INTO db2.a1(f1) valUES(10)");
        User::LeaveIfError(db.Exec(KTabInsert));
                        
        // Attempt to read from the attached non secure database
        _LIT(KSelect,"SELECT * FROM db2.a1");
        User::LeaveIfError(db.Exec(KSelect));
                
        // Attempt to write to the main secure database
        _LIT(KAttachInsert,"INSERT INTO a1(f1) valUES(10)");
        User::LeaveIfError(db.Exec(KAttachInsert));
                
        db.Close();
        iConsole->Printf(KDelete);
        User::LeaveIfError(RSqlDatabase::Delete(KDbName));

        User::LeaveIfError(RSqlDatabase::Delete(KSecureDb2));

        securityPolicy.Close();
        
        }
                
void CSqlExample:: DataTypesQueryL()
        {
        RSqlDatabase db;
        iConsole->Printf(KSecure);
        
        User::LeaveIfError(db.Create(KDbName));

        // Create a table with different numeric field types
        iConsole->Printf(KCreateTable);
        iConsole->Printf(KExecute);
        
        _LIT(KSql1, "CREATE TABLE Tbl(A INTEGER, B SMALLINT, C REAL, D DOUBLE PRECISION, E FLOAT, \
                                                            F DECIMAL)");                                                   
        User::LeaveIfError(db.Exec(KSql1));
        
        // Insert one record in to the created table
        iConsole->Printf(KInsert);                                 
        iConsole->Printf(KExecute);
        
        _LIT(KSql2, "INSERT INTO Tbl(A,B,C,D,E,F) VALUES(2000000000, 30000, 123.45, 0.912E+55,\
                                            1.34E-14, 1234.5678)");
        User::LeaveIfError(db.Exec(KSql2));
        
        // Get the inserted record data
        RSqlStatement stmt;
        iConsole->Printf(KPrepare);
        
        _LIT(KPrepQuery,"SELECT * FROM Tbl");
        User::LeaveIfError(stmt.Prepare(db, KPrepQuery));
        
        User::LeaveIfError(stmt.Next());
        stmt.Close();
        
        // The statement object has to be closed before db.Exec() call, 
        // otherwise the reported error is "database table is locked"
        // Insert second record in to the created table but inverse the column types.
        iConsole->Printf(KExecute);
        _LIT(KSql3, "INSERT INTO Tbl(A,   B,  C, D, E, F) VALUES(\
                                                                                -2.5,1.1,12,23,45,111)");                                                                       
        User::LeaveIfError(db.Exec(KSql3)); 
        
        // Get the inserted record data
        _LIT(KPrepQuery2,"SELECT * FROM Tbl");
        User::LeaveIfError(stmt.Prepare(db, KPrepQuery2));

        User::LeaveIfError(stmt.Next());
        
        stmt.Close();
        
        // Insert third record in to the created table
        _LIT(KSql4, "INSERT INTO Tbl(A,B,C,D,E,F) VALUES(\
                                            2,3,123.45,1.5,2.5,1.56)");
        User::LeaveIfError(db.Exec(KSql4));
        
        stmt.Close();
        db.Close();
        User::LeaveIfError(RSqlDatabase::Delete(KDbName));
        }
        

void CSqlExample::ScalarFullSelectL()
        {
        RSqlDatabase db;
        //Create  database.
        User::LeaveIfError(db.Create(KDatabase));
        
        _LIT(KTabCreateA,"CREATE TABLE A(F1 INTEGER, F2 INTEGER, F3 FLOAT, F4 TEXT, F5 BLOB)");
        User::LeaveIfError(db.Exec(KTabCreateA));
        
        _LIT(KTabInsert1A,"INSERT INTO A(F1, F2, F3, F4, F5) VALUES(1, 10000000000, 2.54, 'NAME1234567890', NULL)");
        User::LeaveIfError(db.Exec(KTabInsert1A));
        
        _LIT(KTabInsert2A,"INSERT INTO A(F1, F2, F3, F4) VALUES(2, 200, -1.11, 'ADDRESS')");    
        User::LeaveIfError(db.Exec(KTabInsert2A));
        
        RSqlStatement stmt;
        CleanupClosePushL(stmt);
        
        _LIT(KUpdate,"UPDATE A SET F5=:P WHERE F1 = 2");
        User::LeaveIfError(stmt.Prepare(db,KUpdate));

        // Open the parameter stream
        RSqlParamWriteStream strm;
        CleanupClosePushL(strm);
        
        // Prepare and set the parameter value (non-NULL value)
        User::LeaveIfError(strm.BindBinary(stmt, 0));

        for(TInt i=0;i<100;++i)
                {
                strm << static_cast <TUint8> (i);       
                }
        // Write the buffered data into stream
        strm.CommitL();
        // Execute the prepared SQL statement   
        User::LeaveIfError(stmt.Exec());        
                
        CleanupStack::PopAndDestroy(&strm);
        CleanupStack::PopAndDestroy(&stmt);
        
        TSqlScalarFullSelectQuery fullSelectQuery(db);

        TBuf<100> sql;
        
        // Query with F2 column (64-bit integer column)
        _LIT(KAnotherSql, "SELECT F2 FROM A WHERE F1 = 1");
        sql.Copy(KAnotherSql);
        // Read F2 as integer.
        TInt valInt = fullSelectQuery.SelectIntL(sql);
                
        // Read F2 as 64-bit integer. Expected value: 10000000000
        TInt64  valInt64 = fullSelectQuery.SelectInt64L(sql);
        
        // Read F2 as real. Expected value: 10000000000.0
        TReal valReal = fullSelectQuery.SelectRealL(sql);
        
        // Read F2 as text. Expected value: zero-length 16-bit descriptor.
        TBuf<10> valText;
        TInt err = fullSelectQuery.SelectTextL(sql, valText);

        // Read F2 as binary. Expected value: zero-length 8-bit descriptor.
        TBuf8<10> valBinary;
        err = fullSelectQuery.SelectBinaryL(sql, valBinary);
        
        // Query with F4 column (text column) 
        _LIT(KSql4, "SELECT F4 FROM A WHERE F1 = 1");
        sql.Copy(KSql4);
        // Read F4 as integer. Expected value: 0.
        valInt = fullSelectQuery.SelectIntL(sql);
        
        //Read F4 as 64-bit integer. Expected value: 0.
        valInt64 = fullSelectQuery.SelectInt64L(sql);
        
        // Read F4 as real. Expected value: 0.0.
        valReal = fullSelectQuery.SelectRealL(sql);
        
        // Read F4 as text. Small buffer. Expected return code: positive value, which is the column length in characters.
        err = fullSelectQuery.SelectTextL(sql, valText);
        
        // Read F4 as text. Big enough buffer. 
        TBuf<32> valText2;
        err = fullSelectQuery.SelectTextL(sql, valText2);
        
        // Read F4 as binary. Expected error: KErrNone. Zero-length 8-bit descriptor.
        err = fullSelectQuery.SelectBinaryL(sql, valBinary);

        // Read F5 as binary. Big enough buffer.
        TBuf8<100> valBinary2;
        err = fullSelectQuery.SelectBinaryL(sql, valBinary2);
        
        // Text column value, small buffer, reallocation 
        HBufC* hbuf = HBufC::NewLC(10);
        TPtr name = hbuf->Des();
        sql.Copy(KSql4);
        err = fullSelectQuery.SelectTextL(sql, name);
        
        if(err > 0)
                {
                hbuf = hbuf->ReAllocL(err);
                CleanupStack::Pop();    
                CleanupStack::PushL(hbuf);
                name.Set(hbuf->Des());
                err = fullSelectQuery.SelectTextL(sql, name);
        
                }
        CleanupStack::PopAndDestroy(); // hbuf, can't be put as parameter, because may be reallocated
        //Close database, delete database file.
        db.Close();
        User::LeaveIfError(RSqlDatabase::Delete(KDatabase));
        
        }
        
void CSqlExample::ColumnBinaryStreamL()
        {
        RSqlDatabase db;
        TInt error;
        User::LeaveIfError(db.Create(KDbName));

        // Create a table
        _LIT(KSqlStmt1, "CREATE TABLE A(Fld1 INTEGER, Fld2 BLOB);");
        
        User::LeaveIfError(error = db.Exec(KSqlStmt1));
        const TInt KDataLen = 100;

        _LIT(KSqlStmt2, "INSERT INTO A(Fld1, Fld2) VALUES(");
        
        // Allocate a buffer for the SQL statement.
        HBufC8* buf = HBufC8::New(KSqlStmt2().Length() + KDataLen * 2 + 10);
        
        TPtr8 sql = buf->Des();
        
        // Insert row 1

        _LIT(KHexValStr1, "7E");
        sql.Copy(KSqlStmt2);
        
        _LIT(KString1, "1, x'");
        sql.Append(KString1);
        TInt i;
        for(i=0;i<KDataLen;++i)
                {
                sql.Append(KHexValStr1);
                }
        _LIT(KString2, "')");   
        sql.Append(KString2);

        User::LeaveIfError(db.Exec(sql));

        // Insert row 2
        
        _LIT(KHexValStr2, "A3");
        sql.Copy(KSqlStmt2);
        _LIT(KString3, "2, x'");
        sql.Append(KString3);
        for(i=0;i<KDataLen;++i)
                {
                sql.Append(KHexValStr2);
                }
        _LIT(KString4, "')");
        sql.Append(KString4);

        User::LeaveIfError(db.Exec(sql));
        
        // Prepare SELECT SQL statement
        _LIT(KSqlStmt3, "SELECT * FROM A");
        
        RSqlStatement stmt;
        User::LeaveIfError(error = stmt.Prepare(db, KSqlStmt3));
        
        // Move on row 1
        User::LeaveIfError(error = stmt.Next());

        // Read the long binary column using a stream
        RSqlColumnReadStream columnStream;
        error = columnStream.ColumnBinary(stmt, 1);
        
        
        TInt size = stmt.ColumnSize(1);
        TPtr8 colData = buf->Des();
        TRAP(error, columnStream.ReadL(colData, size));
        columnStream.Close();
        
        User::LeaveIfError(stmt.Next());
                
        //Read row 2 using ColumnBinary(TInt aColumnIndex, TDes8& aDest).
        error = stmt.ColumnBinary(1, colData);

        //Read row 2 using a stream
        colData.Zero();
        error = columnStream.ColumnBinary(stmt, 1);
        
        size = stmt.ColumnSize(1);
        TRAP(error, columnStream.ReadL(colData, size));
        columnStream.Close();
        
        stmt.Close();
                
        delete buf; 
        buf = NULL;
        
        db.Close();

        error = RSqlDatabase::Delete(KDbName);
        
        }

                                
LOCAL_C void MainL()
        {
        // Create an Active Scheduler to handle asychronous calls
        CActiveScheduler* scheduler = new (ELeave) CActiveScheduler;
        CleanupStack::PushL(scheduler);
        CActiveScheduler::Install( scheduler );
        CSqlExample* app = CSqlExample::NewLC();
        
        // Create a non secure database
        app->CreateNonSecureDBL();
        
        // Create and open a secure database
        app->CreateAndOpenSecureDBL();
        
        // Copy two databases
        app->CopyDatabaseL();
        
        // Attach two databases
        app->AttachDatabasesL();
        
        // Simple query and query with paramaters
        app->DataTypesQueryL();
        
        //Prepares and executes a query with a large parameter
        // writing that parameter using streaming (RParamWriteStream)
        app->ScalarFullSelectL();
        
        // Prepare and execute a query which returns data,
        // and read that data using streaming (RColumnReadStream)
        app->ColumnBinaryStreamL();
                
        CleanupStack::PopAndDestroy(2); //app, scheduler
        
        }

GLDEF_C TInt E32Main()
        {
    __UHEAP_MARK;
    CTrapCleanup* cleanup = CTrapCleanup::New();
    if(cleanup == NULL)
        {
        return KErrNoMemory;
        }
    TRAPD(err, MainL());
        if(err != KErrNone)
                {
                User::Panic(_L("Failed to complete"),err);
                }

    delete cleanup;
    __UHEAP_MARKEND;
    return KErrNone;
        }

---

Copyright ©2010 Nokia Corporation and/or its subsidiary(-ies).
All rights reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License v1.0.