CAML语法-Query写法

1.Geq(>=)
The Geq element is an arithmetic operator that means "greater than or equal to." It can be used within a Where element in a view definition.
<Query>
<Where>
    <Or>
      <IsNull>
        <FieldRef Name="Expires" />
      </IsNull>
      <Geq>
        <FieldRef Name="Expires" />
        <Value Type="DateTime">
          <Today />
        </Value>
      </Geq>
    </Or>
   </Where>
   <OrderBy>
   <FieldRef Name="Modified" Ascending="FALSE" />
</OrderBy>
</Query>
2.Eq(=)
The Eq element is an arithmetic operator that means "equal to" and is used within the Query element.
<Query>
<OrderBy>
    <FieldRef Name="Modified" Ascending="FALSE"></FieldRef>
</OrderBy>
<Where>
    <Or>
      <Eq>
        <FieldRef Name="Status"></FieldRef>
        <Value Type="Text">Completed</Value>
      </Eq>
      <IsNull>
        <FieldRef Name="Status"></FieldRef>
      </IsNull>
    </Or>
</Where>
</Query>
3.Gt(>)
The Gt element is an arithmetic operator that means "greater than." This element is used similarly to Eq and Lt.
<Query>
<Where>
    <Or>
      <IsNull>
        <FieldRef Name="Deadline" />
      </IsNull>
      <Gt>
        <FieldRef Name="Deadline" />
        <Value Type="DateTime">
          <Today />
        </Value>
      </Gt>
    </Or>
</Where>
<OrderBy>
    <FieldRef Name="Modified" Ascending="FALSE" />
</OrderBy>
</Query>
4.Lt(<)
The Lt element is an arithmetic operator that means "less than" and is used in queries in views. This element is used similarly to Eq and Gt.
<Query>
<Where>
    <Or>
      <IsNull>
        <FieldRef Name="Deadline" />
      </IsNull>
      <Lt>
        <FieldRef Name="Deadline" />
        <Value Type="DateTime">
          <Today />
        </Value>
      </Lt>
    </Or>
</Where>
<OrderBy>
    <FieldRef Name="Modified" Ascending="FALSE" />
</OrderBy>
</Query>
5.Neq(!=)
The Neq element is an arithmetic operator that means "not equal to" and is used in queries.
<Query>
<OrderBy>
    <FieldRef Name="Modified" Ascending="FALSE"></FieldRef>
</OrderBy>
<Where>
    <Or>
      <Neq>
        <FieldRef Name="Status"></FieldRef>
        <Value Type="Text">Completed</Value>
      </Neq>
      <IsNull>
        <FieldRef Name="Status"></FieldRef>
      </IsNull>
     </Or>
   </Where>
</Query>

SPQuery 的Where 子句的用法

1、一个条件实例

<Value Type='Text'>Mark</Value></Eq> <Eq><FieldRef

Name='Name'/><Value Type='Text'>Joe</Value></Eq> </Or>

</Where>

2、两个条件实例

<Eq><FieldRef Name='Name'/><Value Type='Text'>Linda</Value></Eq>

</Or> </Or> </Where>

3、三个条件实例

<Eq><FieldRef Name='Name'/><Value Type='Text'>Linda</Value></Eq>

</Or> </Or> </Where>

下表是CAML查询的一些简单说明：

元素	说明
And	并且
BeginsWith	以某字符串开始的
Contains	包含某字符串
Eq	等于
FieldRef	一个字段的引用 (在GroupBy 中使用)
Geq	大于等于
GroupBy	分组
Gt	大于
IsNotNull	非空
IsNull	空
Leq	小于等于
Lt	小于
Neq	不等于
Now	当前时间
Or	或
OrderBy	排序
Today	今天的日期
TodayIso	今天的日期（ISO格式）
Where	Where子句