从DB灌值到DataTable时，字段值为NULL时报错相关信息；

报错信息：

1. 

2. 

3. 

4. 

5. 

6. 

解决方法：

1. Data Layer SQL 语句取数据时，把其列值有为null的字段用0.00替换，（ISNULL的用法）；

2.

        #region 查询工资信息
         /// <summary>
         /// 查询工资信息
         /// </summary>
         /// <param name="model"></param>
         /// <param name="pageIndex"></param>
         /// <param name="pageCount"></param>
         /// <param name="ord"></param>
         /// <param name="TotalCount"></param>
         /// <returns></returns>
         public static DataTable GetSalaryInfoByEmployee(SalaryInfoModel model, string ReportType, string DeptID, int pageIndex, int pageCount, string ord, string endmonth, ref int TotalCount)
         {
             #region 查询语句
             StringBuilder searchSql = new StringBuilder();
             searchSql.AppendLine(" SELECT                                                ");
             searchSql.AppendLine("      A.ID,A.ReprotNo,A.CompanyCD,A.DeptName,A.EmployeeID,A.EmployeeName,A.Remarks,");
             searchSql.AppendLine("isnull(A.BFGJJ,0.00)    BFGJJ,");
             searchSql.AppendLine("isnull(A.BFGZ,0.00)    BFGZ,   ");
             searchSql.AppendLine("isnull(A.BLGZ,0.00)    BLGZ,");
             searchSql.AppendLine("isnull(A.CTF,0.00)    CTF,   ");
             searchSql.AppendLine("isnull(A.DTF,0.00)    DTF,");
             searchSql.AppendLine("isnull(A.FTF,0.00)    FTF,  ");
             searchSql.AppendLine("isnull(A.GHF,0.00)    GHF,");
             searchSql.AppendLine("isnull(A.GJJ,0.00)    GJJ,");
             searchSql.AppendLine("isnull(A.GTS,0.00)    GTS,");
             searchSql.AppendLine("isnull(A.GWF,0.00)    GWF,");
             searchSql.AppendLine("isnull(A.JBGZ,0.00)    JBGZ,");
             searchSql.AppendLine("isnull(A.JiangJ,0.00)    JiangJ,");
             searchSql.AppendLine("isnull(A.JZZYBF,0.00)    JZZYBF,");
             searchSql.AppendLine("isnull(A.KCBJ,0.00)    KCBJ,  ");
             searchSql.AppendLine("isnull(A.MTF,0.00)    MTF, ");
             searchSql.AppendLine("isnull(A.QT,0.00)    QT,  ");
             searchSql.AppendLine("isnull(A.QTE,0.00)    QTE, ");
             searchSql.AppendLine("isnull(A.QTY,0.00)    QTY,   ");
             searchSql.AppendLine("isnull(A.SBJ,0.00)    SBJ,   ");
             searchSql.AppendLine("isnull(A.Total,0.00)    Total,   ");
               searchSql.AppendLine("isnull(A.TotalOne,0.00)    TotalOne, ");
             searchSql.AppendLine("isnull(A.TotalTwo,0.00)    TotalTwo, ");
             searchSql.AppendLine("isnull(A.YBJ,0.00)    YBJ,   ");
             searchSql.AppendLine("isnull(A.YLJ,0.00)    YLJ  ");
             searchSql.AppendLine("     ,c.DeptName  as  DeptWprkName                                              ");
             searchSql.AppendLine("     ,Substring(b.ReportMonth, 1, 4) + '年'              ");
             searchSql.AppendLine("         + Substring(b.ReportMonth, 5, 2) + '月'         ");
             searchSql.AppendLine("         AS ReportMonth                                  ");
             searchSql.AppendLine("     FROM officedba.SalaryInfo a                                         ");
             searchSql.AppendLine("     left join    officedba.SalaryReport b    on    a.ReprotNo=b.ReprotNo                                      ");
             searchSql.AppendLine("     left join    officedba.DeptInfo c    on    b.DeptID=c.ID                                      ");
             searchSql.AppendLine("     left join    officedba.EmployeeInfo d    on    a.employeeID=d.ID                                       ");
             searchSql.AppendLine("     WHERE              ");
             searchSql.AppendLine("      a.CompanyCD = @CompanyCD                            ");
             searchSql.AppendLine("     AND b.ReportType = @ReportType                            ");

             #endregion

             //定义查询的命令
             SqlCommand comm = new SqlCommand();
             //公司代码
             comm.Parameters.Add(SqlHelper.GetParameterFromString("@CompanyCD", model.CompanyCD));
             comm.Parameters.Add(SqlHelper.GetParameterFromString("@ReportType", ReportType));
             UserInfoUtil userInfo = (UserInfoUtil)SessionUtil.Session["UserInfo"];
             if (userInfo.EmployeeID !=  && userInfo.EmployeeID !=  && userInfo.EmployeeID !=  && userInfo.EmployeeID != )
             {
                 searchSql.AppendLine("     AND b.DeptId in (select emp.DepID from officedba.EmpAndDep emp where emp.EmpID=@EmployeeID)         ");
                 comm.Parameters.Add(SqlHelper.GetParameterFromString("@EmployeeID", userInfo.EmployeeID.ToString()));
             }

             #region 页面输入条件
             //员工姓名
             if (!string.IsNullOrEmpty(model.EmployeeName))
             {
                 searchSql.AppendLine("    AND A.EmployeeName LIKE '%' + @EmployeeName + '%' ");
                 comm.Parameters.Add(SqlHelper.GetParameterFromString("@EmployeeName", model.EmployeeName));
             }

             if (!string.IsNullOrEmpty(model.DeptName))
             {
                 searchSql.AppendLine("    AND B.DeptID in (" + model.DeptName + ") ");
                 //comm.Parameters.Add(SqlHelper.GetParameterFromString("@DeptName", model.DeptName));
             }
             //所属月份
             if (!string.IsNullOrEmpty(model.Month))
             {
                 if (endmonth != "")
                 {
                     searchSql.AppendLine("    AND convert(int,b.ReportMonth) between @ReportMonth and @endReportMonth ");
                     comm.Parameters.Add(SqlHelper.GetParameterFromString("@endReportMonth", endmonth));
                 }
                 else
                 {
                     searchSql.AppendLine("    AND convert(int,b.ReportMonth) > @ReportMonth  ");
                 }
                 comm.Parameters.Add(SqlHelper.GetParameterFromString("@ReportMonth", model.Month));

             }

             if (!string.IsNullOrEmpty(DeptID))
             {
                 searchSql.AppendLine("    AND (CHARINDEX(',' +LTRIM(d.DeptID),(@DeptID))>0 or  CHARINDEX(RTRIM(d.DeptID)+',',(@DeptID))>0 or CHARINDEX(LTRIM(d.DeptID),(@DeptID))>0) ");
                 comm.Parameters.Add(SqlHelper.GetParameterFromString("@DeptID", DeptID));
             }
             #endregion

3. SQL  Statements

 SELECT
 A.ID,A.ReprotNo,A.CompanyCD,A.DeptName,A.EmployeeID,A.EmployeeName,A.Remarks,
 isnull(A.BFGJJ,0.00)    BFGJJ,
 isnull(A.BFGZ,0.00)    BFGZ,
 isnull(A.BLGZ,0.00)    BLGZ,
 isnull(A.CTF,0.00)    CTF,
 isnull(A.DTF,0.00)    DTF,
 isnull(A.FTF,0.00)    FTF,
 isnull(A.GHF,0.00)    GHF,
 isnull(A.GJJ,0.00)    GJJ,
 isnull(A.GTS,0.00)    GTS,
 isnull(A.GWF,0.00)    GWF,
 isnull(A.JBGZ,0.00)    JBGZ,
 isnull(A.JiangJ,0.00)    JiangJ,
 isnull(A.JZZYBF,0.00)    JZZYBF,
 isnull(A.KCBJ,0.00)    KCBJ,
 isnull(A.MTF,0.00)    MTF,
 isnull(A.QT,0.00)    QT,
 isnull(A.QTE,0.00)    QTE,
 isnull(A.QTY,0.00)    QTY,
 isnull(A.SBJ,0.00)    SBJ,
 isnull(A.Total,0.00)    Total,
 isnull(A.TotalOne,0.00)    TotalOne,
 isnull(A.TotalTwo,0.00)    TotalTwo,
 isnull(A.YBJ,0.00)    YBJ,
 isnull(A.YLJ,0.00)    YLJ
     ,c.DeptName  as  DeptWprkName
     ,Substring(b.ReportMonth, 1, 4) + '年'
     + Substring(b.ReportMonth, 5, 2) + '月'
     AS ReportMonth
 FROM officedba.SalaryInfo a
 left join    officedba.SalaryReport b    on    a.ReprotNo=b.ReprotNo
 left join    officedba.DeptInfo c    on    b.DeptID=c.ID