using System;
using System.Collections.Generic;
using
System.Data.Entity.Infrastructure;
using System.Linq;
using
System.Linq.Expressions;
using System.Text;
namespace P04DAL
{
/// <summary>
/// 用户表 操作类
///
</summary>
public class User
{
///
<summary>
/// 数据上下文对象
/// </summary>
P05MODEL.LeaveWordBoradEntities db = new P05MODEL.LeaveWordBoradEntities();
//public User()
//{
//
//Predicate<P05MODEL.User> a = delegate(P05MODEL.User u) { return u.uId ==
1; };
// //this.DelBy(ab => ab.uId == 1);
// //P05MODEL.User u = new P05MODEL.User() { uId = 1, uLoginName =
"asdfasdf" };
// //this.Modify(u, "uLoginName");
// //List<P05MODEL.User> list = this.GetListBy(u2 => u2.uId > 1 && u2.uIsDel == false);
// //List<P05MODEL.User> listSorted =
this.GetListBy<int>(u3 => u3.uId > 1, u4 => u4.uId);
//}
#region 1.0 新增 实体 +int Add(P05MODEL.User model)
///
<summary>
/// 新增 实体
/// </summary>
///
<param name="model"></param>
///
<returns></returns>
public int Add(P05MODEL.User
model)
{
db.Users.Add(model);
return
db.SaveChanges();//保存成功后，会将自增的id设置给 model的 主键属性，并返回受影响行数
}
#endregion
#region 2。0 根据 用户 id 删除 +int Del(int uId)
///
<summary>
/// 根据 用户 id 删除
/// </summary>
/// <param name="uId"></param>
///
<returns></returns>
public int Del(int uId)
{
P05MODEL.User usr = new P05MODEL.User() { uId = uId };
db.Users.Attach(usr);
db.Users.Remove(usr);
return db.SaveChanges();
}
#endregion
#region 3.0 根据条件删除 +int DelBy(Expression<Func<P05MODEL.User,
bool>> delWhere)
/// <summary>
/// 3.0
根据条件删除
/// </summary>
/// <param
name="delWhere"></param>
///
<returns></returns>
public int
DelBy(Expression<Func<P05MODEL.User, bool>> delWhere)
{
List<P05MODEL.User> listDeleting =
db.Users.Where(delWhere).ToList();
listDeleting.ForEach(u =>
db.Users.Remove(u));
return db.SaveChanges();
}
#endregion
#region 4.0 修改 +int Modify(P05MODEL.User model, params string[]
proNames)
/// <summary>
/// 4.0 修改，如：
///
P05MODEL.User u = new P05MODEL.User() { uId = 1, uLoginName = "asdfasdf" };
/// this.Modify(u, "uLoginName");
/// </summary>
/// <param name="model">要修改的实体对象</param>
/// <param
name="proNames">要修改的 属性 名称</param>
///
<returns></returns>
public int Modify(P05MODEL.User
model, params string[] proNames)
{
DbEntityEntry entry
= db.Entry<P05MODEL.User>(model);
entry.State =
System.Data.EntityState.Unchanged;
foreach (string proName in
proNames)
{
entry.Property(proName).IsModified
= true;
}
return db.SaveChanges();
}
#endregion
#region 5.0 根据条件查询 +List<P05MODEL.User>
GetListBy(Expression<Func<P05MODEL.User,bool>> whereLambda)
/// <summary>
/// 5.0 根据条件查询 +List<P05MODEL.User>
GetListBy(Expression<Func<P05MODEL.User,bool>> whereLambda)
/// </summary>
/// <param
name="whereLambda"></param>
///
<returns></returns>
public List<P05MODEL.User>
GetListBy(Expression<Func<P05MODEL.User, bool>> whereLambda)
{
return db.Users.Where(whereLambda).ToList();
}
#endregion
#region 5.1 根据条件 排序 和查询 + List<P05MODEL.User>
GetListBy<TKey>
/// <summary>
/// 5.1 根据条件 排序
和查询
/// </summary>
/// <typeparam
name="TKey">排序字段类型</typeparam>
/// <param
name="whereLambda">查询条件 lambda表达式</param>
/// <param
name="orderLambda">排序条件 lambda表达式</param>
///
<returns></returns>
public List<P05MODEL.User>
GetListBy<TKey>(Expression<Func<P05MODEL.User, bool>>
whereLambda, Expression<Func<P05MODEL.User, TKey>> orderLambda)
{
return
db.Users.Where(whereLambda).OrderBy(orderLambda).ToList();
}
#endregion
#region 6.0 分页查询 + List<P05MODEL.User>
GetPagedList<TKey>
/// <summary>
/// 6.0 分页查询
+ List<P05MODEL.User> GetPagedList<TKey>
///
</summary>
/// <param
name="pageIndex">页码</param>
/// <param
name="pageSize">页容量</param>
/// <param
name="whereLambda">条件 lambda表达式</param>
/// <param
name="orderBy">排序 lambda表达式</param>
///
<returns></returns>
public List<P05MODEL.User>
GetPagedList<TKey>(int pageIndex, int pageSize,
Expression<Func<P05MODEL.User, bool>> whereLambda,
Expression<Func<P05MODEL.User, TKey>> orderBy)
{
return db.Users.Where(whereLambda).OrderBy(orderBy).Skip((pageIndex - 1) *
pageSize).Take(pageSize).ToList();
}
#endregion
}
}
基类的参考Expression能传一个lambda表达式,布布扣,bubuko.com
原文地址：http://www.cnblogs.com/sumg/p/3743998.html
