www.pudn.com > DBModule.rar > MainUnit.pas

unit MainUnit; 
 
interface 
 
uses 
  Windows, DB, ADODB, SysUtils, ActiveX; 
 
type 
  PInt                  =       ^Integer; 
  PPInt                 =       ^pInt; 
  PPChar                =       ^PChar; 
  PByte                 =       ^Byte; 
  PWORD                 =       ^WORD; 
  PDWORD                =       ^DWORD; 
  PPointer              =       ^Pointer; 
  PDouble               =       ^Double; 
  PInt64                =       ^Int64; 
 
function StartDB(szDBServer: PChar; bKeepConnect: Integer): Integer; cdecl; 
function SelectCommand(szSql: PChar; pRetBuf: PPointer): Integer; cdecl; 
function ExcuteCommand(szSql: PChar): Integer; cdecl; 
function CloseDB(): Integer; cdecl; 
function FreeAndNilMemory(p: PPointer): Integer; cdecl; 
 
var 
  gConnection : TAdoConnection = nil; 
   
implementation 
 
function StartDB(szDBServer: PChar; bKeepConnect: Integer): Integer; 
begin 
  try 
    CoInitialize(nil); 
    gConnection := TADOConnection.Create(nil); 
    if not Assigned(gConnection) then begin 
      Result := -1; 
      Exit; 
    end; 
    gConnection.ConnectionString := Format('Provider=SQLOLEDB.1;Password=szmobile;Persist Security Info=True;User ID=szmobile;Initial Catalog=SZMOBILEPROJ;Data Source=%s', [szDBServer]); 
    gConnection.LoginPrompt := False; 
    if (bKeepConnect = 1) then 
      gConnection.KeepConnection := True 
    else 
      gConnection.KeepConnection := False; 
    gConnection.Connected := True; 
    Result := 0; 
  except 
    Result := -1; 
  end; 
end; 
 
function SelectCommand(szSql: PChar; pRetBuf: PPointer): Integer; 
var 
  AdoQuery : TADOQuery; 
  //guid : TGUID; 
  nStructSize, i, j : Integer; 
  nRow, nPos : Integer; 
  dwPos, dwStart : DWORD; 
  chTmp : Char; 
  nInt64 : Int64; 
  //szTmp : String; 
begin 
  AdoQuery := nil; 
  try 
    AdoQuery := TADOQuery.Create(nil); 
    if not Assigned(AdoQuery) then begin 
      Result := -1; 
      Exit; 
    end; 
    //CreateGUID(guid); 
    //szTmp := IntToStr(guid.D1) + IntToStr(guid.D2) + IntToStr(guid.D3); 
    //AdoQuery.Name := 'ADOQry_' + szTmp; 
    AdoQuery.Connection := gConnection; 
    AdoQuery.Prepared := True; 
    AdoQuery.Close; 
    AdoQuery.SQL.Text := szSql; 
    AdoQuery.Open(); 
    if (AdoQuery.RecordCount < 1) then 
      begin 
        Result := 0; 
        AdoQuery.Destroy; 
        Exit; 
      end 
    else 
      begin 
        nStructSize := 0; 
        for i := 0 to AdoQuery.FieldCount -1 do begin 
          if (AdoQuery.Fields[i].DataType = ftString) then 
            nStructSize := nStructSize + AdoQuery.Fields[i].DataSize -1 
          else if (AdoQuery.Fields[i].DataType = ftWord) then  //(在Delphi中取出的tinyint类型为word，因此特殊处理) 
            nStructSize := nStructSize + AdoQuery.Fields[i].DataSize -1 
          else 
            nStructSize := nStructSize + AdoQuery.Fields[i].DataSize; 
        end; 
        pRetBuf^ := GetMemory(AdoQuery.RecordCount * nStructSize +10); 
        FillMemory(pRetBuf^, AdoQuery.RecordCount * nStructSize +10, 0); 
        if (pRetBuf^ = nil) then begin 
          Result := -1; 
          AdoQuery.Destroy; 
          Exit; 
        end; 
 
        dwStart := DWORD(pRetBuf^); 
        nRow := 0; 
        while not AdoQuery.Eof do begin 
          dwPos := nRow * nStructSize; 
          for i := 0 to AdoQuery.Fields.Count -1 do begin 
            case AdoQuery.Fields[i].DataType of 
              ftString : 
                begin 
                  if AdoQuery.Fields[i].IsNull then 
                    begin 
                      FillMemory(Pointer(dwStart + dwPos), AdoQuery.Fields[i].DataSize -1, 0); 
                    end 
                  else 
                    begin 
                      StrPCopy(Pointer(dwStart + dwPos), AdoQuery.Fields[i].AsString); 
                      nPos := 0; 
                      for j := AdoQuery.Fields[i].DataSize -3 downto 0 do begin 
                        chTmp := PChar(dwStart + dwPos + DWORD(j))^; 
                        if (chTmp <> Chr(32)) and (chTmp <> Chr(0)) then begin 
                          PChar(dwStart + dwPos + DWORD(j) +1)^ := Chr(0); 
                          nPos := dwStart + dwPos + DWORD(j); 
                          Break; 
                        end; 
                      end; 
                      if (nPos = 0) then begin 
                        FillMemory(Pointer(dwStart + dwPos), AdoQuery.Fields[i].DataSize, 0); 
                      end; 
                    end; 
                end; 
              ftWord : //(在Delphi中取出的tinyint类型为word，因此特殊处理) 
                begin 
                  if AdoQuery.Fields[i].IsNull then 
                    PByte(dwStart + dwPos)^ := 0 
                  else 
                    PByte(dwStart + dwPos)^ := Byte(AdoQuery.Fields[i].AsInteger); 
                end; 
              ftSmallint : 
                begin 
                  if AdoQuery.Fields[i].IsNull then 
                    PWORD(dwStart + dwPos)^ := 0 
                  else 
                    PWORD(dwStart + dwPos)^ := WORD(AdoQuery.Fields[i].AsInteger); 
                end; 
              ftInteger : 
                begin 
                  if AdoQuery.Fields[i].IsNull then 
                    PInt(dwStart + dwPos)^ := 0 
                  else 
                    PInt(dwStart + dwPos)^ := AdoQuery.Fields[i].AsInteger; 
                end; 
              ftFloat : 
                begin 
                  if AdoQuery.Fields[i].IsNull then 
                    PDouble(dwStart + dwPos)^ := 0.0 
                  else 
                    PDouble(dwStart + dwPos)^ := AdoQuery.Fields[i].AsFloat; 
                end; 
              ftBytes, ftVarBytes, ftFixedChar : 
                begin 
                  if (AdoQuery.Fields[i].IsNull) then 
                    FillMemory(Pointer(dwStart + dwPos), AdoQuery.Fields[i].DataSize, 0) 
                  else 
                    AdoQuery.Fields[i].GetData(Pointer(dwStart + dwPos)); 
                end; 
              ftBlob : 
                begin 
                  FillMemory(Pointer(dwStart + dwPos), AdoQuery.Fields[i].DataSize, 0); 
                end; 
              ftLargeint : 
                begin 
                  AdoQuery.Fields[i].GetData(@nInt64); 
                  PInt64(dwStart + dwPos)^ := nInt64; 
                end; 
            end; 
            if (AdoQuery.Fields[i].DataType = ftString) then 
              dwPos := dwPos + DWORD(AdoQuery.Fields[i].DataSize -1) 
            else if (AdoQuery.Fields[i].DataType = ftWord) then 
              dwPos := dwPos + DWORD(AdoQuery.Fields[i].DataSize) -1 
            else 
              dwPos := dwPos + DWORD(AdoQuery.Fields[i].DataSize); 
          end; 
          AdoQuery.Next; 
          nRow := nRow +1; 
        end; 
      end; 
 
      Result := AdoQuery.RecordCount; 
  except 
    Result := -1; 
  end; 
 
  if Assigned(AdoQuery) then begin 
    AdoQuery.Destroy; 
  end; 
 
end; 
 
function ExcuteCommand(szSql: PChar): Integer; 
var 
  AdoQuery : TADOQuery; 
begin 
  AdoQuery := nil; 
  try 
    AdoQuery := TADOQuery.Create(nil); 
    if not Assigned(AdoQuery) then begin 
      Result := -1; 
      Exit; 
    end; 
    AdoQuery.Connection := gConnection; 
    AdoQuery.Prepared := True; 
    AdoQuery.Close; 
    AdoQuery.SQL.Text := szSql; 
    AdoQuery.ExecSQL(); 
    Result := 1; 
  except 
    Result := -1; 
  end; 
 
  if Assigned(AdoQuery) then begin 
    AdoQuery.Destroy; 
  end; 
end; 
 
function CloseDB(): Integer; 
begin 
  if Assigned(gConnection) then begin 
    gConnection.Connected := False; 
    gConnection.Destroy(); 
  end; 
  CoUninitialize(); 
  Result := 1; 
end; 
 
function FreeAndNilMemory(p: PPointer): Integer; 
begin 
  FreeMemory(p^); 
  p^ := nil; 
  Result := 1; 
end; 
 
 
end.