Serialized Adodataset, Adoquery (reprint)

The server directly converts the data from the Tadoquery query directly to the Tstream itself for delivery to the client to restore the stream with a Tadoquery object.

Method One < reprint >

is to save the recordset as a stream interface, turn into Olevariant, write the inflow

class function Tadotools.savetostream2 (  pvdataset:tcustomadodataset): Tmemorystream;var   astream:_stream;   V:olevariant;   P:pointer;begin   astream:=costream.create;   Olevariant (Pvdataset.recordset). Save (Astream, ADPERSISTADTG);   astream.position:=0;   V:=astream.read (astream.size);   Result:=tmemorystream.create;   Try     p:=vararraylock (V);     Try       result. Size:=vararrayhighbound (v,1) +1;       Move (P^,result. memory^, result. Size);     Finally       Vararrayunlock (V);     End;   Except     result. Free ();     Result: = nil;     raise;   End;end;

　　

class procedure tadotools.loadfromstream2 (pvdataset:tcustomadodataset;   Pvstream:tmemorystream); var v:olevariant;   Ar:_recordset;   Astream:_stream;   P:pointer;begin pvstream.position:=0; Olevariant (Pvdataset.recordset).   Open (Tstreamadapter.create (Pvstream) as IUnknown, ADPERSISTADTG); Ar.   Open (Astream, emptyparam,adopenunspecified, adLockUnspecified,-1);   Pvdataset.recordset:=adoint._recordset (AR);   V:=vararraycreate ([0,pvstream.size-1], varbyte);   P:=vararraylock (V);   Try Move (pvstream.memory^, p^, pvstream.size);   Finally Vararrayunlock (V);   End   Astream:=costream.create;   Astream.open (Emptyparam,admodeunknown,adopenstreamunspecified, ",");   Astream.type_:=adtypebinary;   Astream.write (V);   Ar:=_recordset (corecordset.create);   astream.position:=0; Ar.   Open (astream,emptyparam,adopenunspecified, adLockUnspecified,-1); Pvdataset.recordset:=adoint._recordset (AR); end; 

Method Two: Directly call the Recordset to save the stream borrowing Tstreamadapter

Class procedure Tadotools.savetostream (Pvdataset:tcustomadodataset; pvstream:tstream); Begin   Olevariant ( Pvdataset.recordset). Save (Tstreamadapter.create (Pvstream) as IUnknown,      ADPERSISTADTG);    Adpersistxmlend;class procedure Tadotools.loadfromstream (pvdataset:tcustomadodataset;  Pvstream:tstream); var   ar:_recordset;begin   Ar:=_recordset (corecordset.create);   pvstream.position:=0;   Ar. Open (Tstreamadapter.create (Pvstream) as IUnknown, Emptyparam,adopenunspecified, adLockUnspecified,-1);   Pvdataset.recordset:=adoint._recordset (AR); end;

　　

Serialized Adodataset, Adoquery (reprint)