那些 Cynthia 教我的事 之 PMSec (二)

一、在Foreach之前要判断是否为空。

常常从数据库里取出来表就直接用了，很少记得判断是否有值。不严谨的说。

专业人员写的是酱滴。。。

1           DataLayer.PMSecDataSet.PMSECRequestDataTable requestDataTable = adapter.up_PMSec_PMSECRequestSelectByMasterIDs(masterIds);
2
3           if (requestDataTable != null && requestDataTable.Count > 0)
4           {
5              ...
6            }

二、当数据库中允许为空。

话说，上次已经说过的啦。。。但是这次更加明确，要用Nullable<int>.

 1          Nullable<int> intNull = null;
 2           DataLayer.PMSecDataSet.PMSECRequestDataTable requestDataTable = adapter.up_PMSec_PMSECRequestSelectByMasterIDs(masterIds);
 3
 4           if (requestDataTable != null && requestDataTable.Count > 0)
 5           {
 6
 7               foreach (DataLayer.PMSecDataSet.PMSECRequestRow dr in requestDataTable.Rows)
 8               {
 9                   PMSecRequestInfo requestInfo = new PMSecRequestInfo();
10                   requestInfo.RequestMasterID = dr.RequestMasterID;
11                   requestInfo.EmployeeID = dr.EmployeeID;
12                   Employee requestEmployee = new Employee(dr.EmployeeID);
13                   requestInfo.DisplayName = requestEmployee.DisplayName;
14                   requestInfo.StatusType = dr.StatusType;
15                   requestInfo.CompanyID = dr.CompanyID;
16                   requestInfo.WorkStoreID = dr.WorkStoreID;
17                   requestInfo.JobCode = dr.JobCode;
18                   requestInfo.RequestedSecurityLevel = dr.IsRequestedSecurityLevelNull() ? intNull : dr.RequestedSecurityLevel;
19                   requestInfo.IsSecurityAdmin = dr.IsSecurityAdmin;
20                   requestInfo.CreatedBy = dr.CreatedBy;
21                   requestInfo.CreatedOn = dr.CreatedOn;
22
23                   requestInfoList.Add(requestInfo);
24               }
25           }

string类无需此处理。

三、操作数据库时

当含有update等更改数据库内容的语句存在时，如果下面操作仍与数据库有关，考虑到程序的扩展性，可能出现上述语句删除了某些数据，下面语句出现异常，或者产生错误结果，等等。

譬如下面两段代码，前者是我的做法，后者为Cynthia的做法，一见高下啊啊啊。我写的好像是舒克和贝塔里那只笨猫，喵，~~~~(>_<)~~~~ 。

 1   public void ApporveOrDeclineRequest(string masterIds, string statusType, int loginEid)
 2       {
 3            PMSECRequestPendingTaskTableAdapter adapter = new PMSECRequestPendingTaskTableAdapter();
 4            adapter.up_PMSec_PMSECRequestUpdate(masterIds, statusType, loginEid);
 5
 6           // Send Email
 7            PandaRG.Common.OrgChart.Employee logInEmployee = new Common.OrgChart.Employee(loginEid);
 8
 9            if (statusType == RequestStatusType.APPROVED.ToString())
10            {
11                EmailSendHelper.SentEmailbyEmailType(RequestStatusType.APPROVED, GetRequestInfoListByRequestMasterIds(masterIds), logInEmployee);
12
13            }
14            else if(statusType==RequestStatusType.DECLINED.ToString())
15            {
16                EmailSendHelper.SentEmailbyEmailType(RequestStatusType.DECLINED, GetRequestInfoListByRequestMasterIds(masterIds), logInEmployee);
17            }
18       }

1       public void UpdatePMSECRequest(string masterIds, RequestStatusType statusType, Employee loginEmployee)
2       {
3           PMSECRequestPendingTaskTableAdapter adapter = new PMSECRequestPendingTaskTableAdapter();
4
5           List<PMSecRequestInfo> requestInfoList = GetRequestInfoListByRequestMasterIds(masterIds);
6           adapter.up_PMSec_PMSECRequestUpdate(masterIds, statusType.ToString(), loginEmployee.EmployeeId);
7           EmailSendHelper.SentEmailbyEmailType(statusType, requestInfoList, loginEmployee);
8       }

四、 λ 表达式

好复杂的说，不老明白的，计入λ 番外篇吧。

( ^_^ )/~~