数据库问题
检查有没有数据，有则修改，无则添加

SQL code

        with ADOQuery1 do        begin             Close;          SQL.Clear;          SQLString :='select * from session where type=1 and Owner='+quotedstr(templogin.Accounts)+' and Name='+quotedstr(TempLogin.Name);          SQL.Add(SQLString);          Open;        end;        if ADOQuery1.RecordCount<>0 then        begin          with  ADOQuery1 do          begin            Close;            SQL.Clear;            SQLString:='UPDate Session SET LocalIP='+quotedstr(TempLogin.RemoteIP)+', LocalPort='+(IntToStr(TempLogin.RemotePort))+                                          ', EngineServerIP='+quotedstr(TempLogin.ServerIP)+', EngineServerPort='+IntToStr(TempLogin.ServerPort)+', Online='+inttostr(1)+                                          ' where type=1 and owner='+quotedstr(TempLogin.Accounts)+' and name='+quotedstr(TempLogin.Name);            SQL.Add(SQLString);            ExecSQL;          end;        end        else        begin          with ADOQuery1 do          begin            Close;            SQL.Clear;            SQLString :='Insert into Session (type, Owner, Name, LocalIP, LocalPort, EngineServerIP, EngineServerPort, Online) VALUES '+'('+                                             IntToStr(1)+','+quotedstr(TempLogin.Accounts)+','+quotedstr(TempLogin.Name)+','+quotedstr(TempLogin.RemoteIP)+','+                                             IntToStr(TempLogin.RemotePort)+','+quotedstr(TempLogin.ServerIP)+','+inttostr(TempLogin.RemotePort)+','+inttostr(1)+')';            SQL.Add(SQLString);            ExecSQL;          end;        end;

修改

SQL code

      with ADOQuery1 do      begin        Close;        SQLstring :='update session set Online='+inttostr(0)+'where Owner='+quotedstr(Accounts)+'and Name='+quotedstr(RName);        SQL.Add(SQLstring);        ShowMsg(SQLstring);        ExecSQL;      end;

为什么修改数据的数据的时候，会自动添加一行呢？就等于又执行了一次：UPDate Session SET
哪里错误啊？还有，我刚学数据库，这样写代码有错误吗？

[解决办法]
若要核实sql语句也不难：
ShowMsg(ADOQuery1.SQL.Text);