Visual C++中使用OLE DB读写SQL Server简明指南

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y2~cs#HHRESULT CSequentialStream::PreAllocBuffer( ULONG uSize )软件测试技术门户2nv_"u |)@[0{
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    if( m_uBufferSize < uSize )软件测试技术门户S:u/n3t'D|g]
    {软件测试技术门户W8EWO$w)G)`#Q^
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        m_uBufferSize = uSize;
'GbN [L,H)eG{2A0G        m_pBuffer = CoTaskMemRealloc( m_pBuffer, m_uBufferSize );
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~        if( m_pBuffer == NULL )
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/h1[i/A'g(Y~"o8e            Clear( );
VlX*P+J0Ul3u            return STG_E_INSUFFICIENTMEMORY;
:N:L"B0E7mg        }
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m.|"]:PF"Cx]?    return S_OK;
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]w7D Z6j iHRESULT CSequentialStream::Read( void* pv, ULONG cb, ULONG* pcbRead )软件测试技术门户zkd6AN Y)T
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    ( pcbRead != NULL ? ( * pcbRead = 0U ) : 0 );
/L*|z2zV    if( pv == NULL ) { return STG_E_INVALIDPOINTER; }软件测试技术门户#X6`q{$O'tP:h3k
    if( cb == 0U ) { return S_OK; }软件测试技术门户 ~/iUKK z
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    ASSERT( m_uPosition <= m_uBufferUsed );软件测试技术门户iG Bt-n8fMb(w-fGna
    ULONG uBytesLeft = m_uBufferUsed - m_uPosition;
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4wc,iX _%A    if( uBytesLeft == 0U ) { return S_FALSE; } //no more bytes软件测试技术门户B&Wa,mh3}T
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    ULONG uBytesRead = ( cb > uBytesLeft ? uBytesLeft : cb );
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