C# 如何检查;id";如果为null或空,则默认值为0或空字符串?
我在C#中使用LINQ编写代码。代码工作正常,但当我尝试测试时,我没有得到任何值,因为没有数据,我知道如果id为null或为空,它将跳过LINQ查询。如果跳过LINQ查询,如何将查询结果的值设置为零或空字符串C# 如何检查;id";如果为null或空,则默认值为0或空字符串?,c#,linq,C#,Linq,我在C#中使用LINQ编写代码。代码工作正常,但当我尝试测试时,我没有得到任何值,因为没有数据,我知道如果id为null或为空,它将跳过LINQ查询。如果跳过LINQ查询,如何将查询结果的值设置为零或空字符串 var Rs1 = _context.DwPropertyDetails.Where(x => x.LandId == id && x.TransactionPrice != null) .Select(x => new
var Rs1 = _context.DwPropertyDetails.Where(x => x.LandId == id && x.TransactionPrice != null)
.Select(x => new
{
Studio = x.FlatType.ToLower() == studio.ToLower() ? x.TransactionPrice : 0,
OneBedroom = x.FlatType.ToLower() == onebedroom.ToLower() ? x.TransactionPrice : 0,
TwoBedroom = x.FlatType.ToLower() == twobedroom.ToLower() ? x.TransactionPrice : 0,
ThreeBedroom = x.FlatType.ToLower() == threebedroom.ToLower() ? x.TransactionPrice : 0,
Total = x.TransactionPrice
}).Select(a => new
{
a.Studio,
a.OneBedroom,
a.TwoBedroom,
a.ThreeBedroom,
a.Total,
Dummy = "x"
}).GroupBy(a => new { a.Dummy })
.Select(g => new
{
Rs1Clm2 = totalTransAmount,
Rs1Clm3 = g.Sum(p => p.Studio),
Rs1Clm4 = g.Sum(p => p.OneBedroom),
Rs1Clm5 = g.Sum(p => p.TwoBedroom),
Rs1Clm6 = g.Sum(p => p.ThreeBedroom),
Rs1Clm7 = g.Sum(p => p.Total),
});
好吧,我在风景区试试看
<tbody>
@if (Model == null || string.IsNullOrEmpty(Model.Rs1Vms.ToString()) || string.IsNullOrWhiteSpace(Model.Rs1Vms.ToString()))
{
<tr>
<td>Total Transaction Amount</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
}
else
{
foreach (var a in Model.Rs1Vms)
{
<tr>
<td>@Html.DisplayFor(model => a.Rs1Vm2)</td>
<td>@($"{a.Rs1Vm3:N0}")</td>
<td>@($"{a.Rs1Vm4:N0}")</td>
<td>@($"{a.Rs1Vm5:N0}")</td>
<td>@($"{a.Rs1Vm6:N0}")</td>
<td>@($"{a.Rs1Vm7:N0}")</td>
</tr>
}
}
</tbody>
@if(Model==null | | string.IsNullOrEmpty(Model.Rs1Vms.ToString())| | string.IsNullOrWhiteSpace(Model.Rs1Vms.ToString())
{
交易总额
0
0
0
0
0
}
其他的
{
foreach(Model.Rs1Vms中的变量a)
{
@DisplayFor(model=>a.Rs1Vm2)
@($“{a.Rs1Vm3:N0}”)
@($“{a.Rs1Vm4:N0}”)
@($“{a.Rs1Vm5:N0}”)
@($“{a.Rs1Vm6:N0}”)
@($“{a.Rs1Vm7:N0}”)
}
}
您可以使用DefaultIfEmpty执行此任务
var Rs2 = Rs1.DefaultIfEmpty(new
{
Rs1Clm2 = 0,
Rs1Clm3 = 0,
Rs1Clm4 = 0,
Rs1Clm5 = 0,
Rs1Clm6 = 0,
Rs1Clm7 = 0,
});
您可以使用DefaultIfEmpty执行此任务
var Rs2 = Rs1.DefaultIfEmpty(new
{
Rs1Clm2 = 0,
Rs1Clm3 = 0,
Rs1Clm4 = 0,
Rs1Clm5 = 0,
Rs1Clm6 = 0,
Rs1Clm7 = 0,
});
我以前试过这个。但是在风景区呢?我以前试过这个。但是在风景中呢?