/* 创建者：菜刀居士的博客
* 创建日期：2014年07月08号
*/

namespace Net.CRM.FetchXml
{
using System;
using Microsoft.Xrm.Sdk;
using Microsoft.Xrm.Sdk.Query;

/// <summary>
/// 使用FetchXml聚合查询
/// </summary>
public class FetchXmlDemo
{
/* 特别提示：FetchXML 包括使您能够计算总和、平均值、最小值、最大值和计数的分组和聚合函数。
* 在查询中只能指定一个 aggregate 属性，而且不能使用 distinct 关键字。要创建的聚合的属性，
* 请设置关键字aggregate到true，然后指定有效的实体名称， 属性名称，和别名 （变量名）。
* 同时必须指定要执行的聚合的类型。
*/

/// <summary>
/// 总和
/// sql: select sum(new_value) as 'new_value_sum' from account
/// </summary>
public void Sum(IOrganizationService service)
{
string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'>
<entity name='account'>
<attribute name='new_value' alias='new_value_sum' aggregate='sum' />
</entity>
</fetch>";
EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml));
if (ec != null && ec.Entities.Count > 0)
{
Entity en = ec.Entities[0];
//获取结果
decimal value = ((Money)((AliasedValue)en["new_value_sum"]).Value).Value;
}
}

/// <summary>
/// 平均值
/// sql: select avg(new_value) as 'new_value_avg' from account
/// 当crm计算数据的平均值时，不考虑 Null 值。但是，会使用零 (0)。
/// </summary>
public void Avg(IOrganizationService service)
{
string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'>
<entity name='account'>
<attribute name='new_value' alias='new_value_avg' aggregate='avg' />
</entity>
</fetch>";
EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml));
if (ec != null && ec.Entities.Count > 0)
{
Entity en = ec.Entities[0];
//获取结果
decimal value = ((Money)((AliasedValue)en["new_value_avg"]).Value).Value;
}
}

/// <summary>
/// 计算有多少个记录
/// sql: select count(*) from account
/// </summary>
public void Count(IOrganizationService service)
{
string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'>
<entity name='account'>
<attribute name='new_name' alias='new_name_count' aggregate='count' />
</entity>
</fetch>";
EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml));
if (ec != null && ec.Entities.Count > 0)
{
Entity en = ec.Entities[0];
//获取结果
int value = (Int32)((AliasedValue)en["new_name_count"]).Value;
}
}

/// <summary>
/// 计算有多少个记录(针对指定的列名)
/// sql: select count(distinct new_name) from account
/// </summary>
public void CountColumn(IOrganizationService service)
{
string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'>
<entity name='account'>
<attribute name='new_name' alias='new_name_count' aggregate='countcolumn' distinct='true' />
</entity>
</fetch>";
EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml));
if (ec != null && ec.Entities.Count > 0)
{
Entity en = ec.Entities[0];
//获取结果
int value = (Int32)((AliasedValue)en["new_name_count"]).Value;
}
}

/// <summary>
/// 最大值
/// sql: select max(new_value) as 'new_value_max' from account
/// 当crm计算数据的最大值时，不考虑 Null 值。但是，会使用零 (0)。
/// </summary>
public void Max(IOrganizationService service)
{
string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'>
<entity name='account'>
<attribute name='new_value' alias='new_value_max' aggregate='max' />
</entity>
</fetch>";
EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml));
if (ec != null && ec.Entities.Count > 0)
{
Entity en = ec.Entities[0];
//获取结果
decimal value = ((Money)((AliasedValue)en["new_value_max"]).Value).Value;
}
}

/// <summary>
/// 最小值
/// sql: select min(new_value) as 'new_value_min' from account
/// 当crm计算数据的最小值时，不考虑 Null 值。但是，会使用零 (0)。
/// </summary>
public void Min(IOrganizationService service)
{
string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'>
<entity name='account'>
<attribute name='new_value' alias='new_value_min' aggregate='min' />
</entity>
</fetch>";
EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml));
if (ec != null && ec.Entities.Count > 0)
{
Entity en = ec.Entities[0];
//获取结果
decimal value = ((Money)((AliasedValue)en["new_value_min"]).Value).Value;
}
}

/// <summary> /// 多个聚合 /// sql: select count(*) as 'new_value_count',max(new_value) as 'new_value_max',/// min(new_value) as 'new_value_min' from account /// </summary> public void CountAndMaxAndMin(IOrganizationService service) { string fetchXml = @"<fetch distinct='false' mapping='logical' aggregate='true'> <entity name='account'> <attribute name='new_value' alias='new_value_count' aggregate='count' /> <attribute name='new_value' alias='new_value_max' aggregate='max' /> <attribute name='new_value' alias='new_value_min' aggregate='min' /> </entity> </fetch>"; EntityCollection ec = service.RetrieveMultiple(new FetchExpression(fetchXml)); if (ec != null && ec.Entities.Count > 0) { Entity en = ec.Entities[0]; //获取结果 int count_value = (Int32)((AliasedValue)en["new_value_count"]).Value; decimal max_value = ((Money)((AliasedValue)en["new_value_max"]).Value).Value; decimal min_value = ((Money)((AliasedValue)en["new_value_min"]).Value).Value; } } } }