symbian 數據庫字段長度

 

 TDbCol(const TDesC& aName,TDbColType aType); 

 TDbCol(const TDesC& aName,TDbColType aType,TInt aMaxLength); 

 

 

  EDbColText  ： 默認長度  50， 自定義長度  aMaxLength

  EDbColLongText ：基本不限制長度，但需要用流讀寫，如：

 

 

 

void CDBColStream::WriteStream( RDbTable& atable, TDbColNo aCol, const TDesC& adescription )

{

RDbColWriteStream writeStream;

    writeStream.OpenLC(atable,aCol);

writeStream.WriteL(adescription);

writeStream.Close();

CleanupStack::Pop();

}

 

void CDBColStream::ReadStream( RDbTable& atable, TDbColNo aCol, HBufC* description )

{

TInt length = atable.ColLength(aCol);

RDbColReadStream readStream; 

readStream.OpenLC(atable,aCol);

TPtr16 temp(description->Des());

readStream.ReadL(temp,length);

 

readStream.Close();

CleanupStack::Pop(); //readStream

}