Sharepoint学习笔记---Linq to Sharepoint--如何获取Linq Query 生成的CALM
我们知道Linq to sharepoint 实际最终还是转化成了CALM来对Sharepoint进行访问,那么我们怎样才能知道我们编写的Query语句最终转化成的CALM语句是什么样子呢。 我们可以使用如下方法来达到我们的目的。1.首先在我们的Sharepoint项目中新建一个名为CAMLDebug的类，如图:
CALMDebug.cs代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using Microsoft.SharePoint.Linq;
namespace NorthwindLinqToSP
{
public class CAMLDebug : IDisposable
{
private DataContext _context;
public StringWriter Writer
{
get;
private set;
}
public CAMLDebug(DataContext context)
{
_context = context;
Writer = new StringWriter();
_context.Log = Writer;
}
public override string ToString()
{
Writer.Flush();
return Writer.GetStringBuilder().ToString();
}
public void Dispose()
{
_context.Log = null;
Writer.Dispose();
}
}
} 2.然后在我们的Linq to sharepoint 代码中使用此类
var dc = new NorthWindEntityDataContext(SPContext.Current.Web.Url);
MyCustomers = dc.GetList<ACustomerItem>("ACustomer");
MyOrders = dc.GetList<AOrdersItem>("AOrders");
using (CAMLDebug debug = new CAMLDebug(dc))
{
string queries = debug.ToString();
var query = from c in MyCustomers
where (from o in MyOrders
select o.BCSFindCustomerID).Contains(c.BCSFindCustomerID)
select c;
this.lblMsg2.Text = "Items :" + query.Count().ToString();
this.gvDetails.DataSource = query;
this.gvDetails.DataBind();
} 3.在代码段中设置断点，进入调试（当然，你也可以把queries保存的CALM字串输出到你想要的任何地方）
4.此处，也有人不用上面的类，而直接使用如下代码把生成的CALM直接输出到指定的txt文件中进行查看。
var dc = new NorthWindEntityDataContext(SPContext.Current.Web.Url);
MyCustomers = dc.GetList<ACustomerItem>("ACustomer");
MyOrders = dc.GetList<AOrdersItem>("AOrders");
TextWriter textWriter = new StreamWriter(@"c:\caml.txt", false);
dc.Log = textWriter;
var query = from c in MyCustomers
where !(from o in MyOrders
select o.BCSFindCustomerID).Contains(c.BCSFindCustomerID)
select new
{
CopanyName = c.BCSFindCompanyName,
ContanctName = c.BCSFindContactName,
Address = new
{
Country = c.BCSFindCountry,
City = c.BCSFindCity,
PostalCode = c.BCSFindPostalCode
}
};
this.lblMsg2.Text = "Items :" + query.Count().ToString();
this.gvDetails.DataSource = query;
this.gvDetails.DataBind(); 上述代码输出的结果如下图:
接下来的任务就是在你的SPQuery 中进行引用了(以下是一个引用样例，仅作参考)
SPQuery query = new SPQuery();
query.Query = @"<Where>
<And>
<BeginsWith>
<FieldRef Name='ContentTypeId' />
<Value Type='ContentTypeId'>0x0100</Value>
</BeginsWith>
<BeginsWith>
<FieldRef Name='ProductContentTypeId' />
<Value Type='Lookup'>0x0100</Value>
</BeginsWith>
</And>
</Where>
<OrderBy Override='TRUE' />";
query.ViewFields = @"<FieldRef Name='Title' />
<FieldRef Name='ProductProductName' />";
query.ProjectedFields = @"<Field Name='ProductProductName' Type='Lookup'
List='AProduct' ShowField='ProductName' />
<Field Name='ProductContentTypeId' Type='Lookup'
List='AProduct' ShowField='ContentTypeId' />";
query.Joins = @"<Join Type='INNER' ListAlias='AProduct'>
<Eq>
<FieldRef Name='Product' RefType='ID' />
<FieldRef List='Product' Name='ID' />
</Eq>
</Join>";
query.RowLimit = 2657495668;
var list = web.Lists["AOrders"];
var items = list.GetItems(query);
foreach (SPListItem item in items)
{
this.ListBoxOutPut.Items.Add(item["Title"]+ item["ProductProductName"]));
}
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