Question

我有以下内容：

var result =
    from entry in feed.Descendants(a + "entry")
    let content = entry.Element(a + "content")
    let properties = content.Element(m + "properties")
    let text = properties.Element(d + "Text")
    let title = properties.Element(d + "Title")
    let partitionKey = properties.Element(d + "PartitionKey")
    select new Content
    {
        Text = text.Value,
        Title = title.Value
    };

我想要做的是添加一个位置，以便只将一些项目放入结果中。我该如何添加条件：

partitionKey.Substring(2, 2) == "03" && text != null

选择？

Answer 1

只需在选择前添加条件：

var result =
    from entry in feed.Descendants(a + "entry")
    let content = entry.Element(a + "content")
    let properties = content.Element(m + "properties")
    let text = properties.Element(d + "Text")
    let title = properties.Element(d + "Title")
    let partitionKey = properties.Element(d + "PartitionKey")
    where partitionKey.Value.Substring(2, 2) == "03"
    where text != null
    select new Content
    {
        Text = text.Value,
        Title = title.Value
    };

Answer 2

而不是

where partitionKey.Substring(2, 2) == "03" && text != null

使用

where partitionKey.Value.Substring(2, 2) == "03" && text != null

partitionKey的类型为XElement，当您需要它的值时。

Answer 3

在where：

之前指定select

var result =
    from entry in feed.Descendants(a + "entry")
    let content = entry.Element(a + "content")
    let properties = content.Element(m + "properties")
    let text = properties.Element(d + "Text")
    let title = properties.Element(d + "Title")
    let partitionKey = properties.Element(d + "PartitionKey")
    where partitionKey.Substring(2, 2) == "03" && text != null
    select new Content
    {
        Text = text.Value,
        Title = title.Value
    };

Answer 4

        var result =
from entry in feed.Descendants(a + "entry")
let content = entry.Element(a + "content")
let properties = content.Element(m + "properties")
let text = properties.Element(d + "Text")
let title = properties.Element(d + "Title")
let partitionKey = properties.Element(d + "PartitionKey")
where partitionKey.Value.Substring(2, 2) == "03" && text != null
select new Content
{
    Text = text.Value,
    Title = title.Value
};

Answer 5

我建议使用linquer软件将SQL脚本转换为LINQ，想象一下在Inner Joins和更多complecx查询时？

访问：www.sqltolinq.com/

这是非常方便的工具!!

如何在LINQ中的select中添加where子句？

5 个答案: