DbContext通用数据仓储类
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/// <summary>
/// 数据仓储类
/// </summary>
/// <typeparam name="T">实体模型</typeparam>
public class Repository<T> where T : class
{
/// <summary>
/// 数据上下文
/// </summary>
public DbContext DbContext { get; set; }
public Repository()
{ }
/// <summary>
/// 构造函数
/// </summary>
/// <param name="dbContext">数据上下文</param>
public Repository(DbContext dbContext)
{
DbContext = dbContext;
}
//查找实体
#region Find
/// <summary>
/// 查找实体
/// </summary>
/// <param name="ID">实体主键值</param>
/// <returns></returns>
public T Find(int ID)
{
return DbContext.Set<T>().Find(ID);
}
/// <summary>
/// 查找实体
/// </summary>
/// <param name="where">查询Lambda表达式</param>
/// <returns></returns>
public T Find(Expression<Func<T, bool>> where)
{
return DbContext.Set<T>().SingleOrDefault(where);
}
#endregion
//查找实体列表
#region FindList
/// <summary>
/// 查找实体列表
/// </summary>
/// <returns></returns>
public IQueryable<T> FindList()
{
return DbContext.Set<T>();
}
/// <summary>
/// 查找实体列表
/// </summary>
/// <param name="where">查询Lambda表达式</param>
/// <returns></returns>
public IQueryable<T> FindList(Expression<Func<T, bool>> where)
{
return DbContext.Set<T>().Where(where);
}
/// <summary>
/// 查找实体列表
/// </summary>
/// <param name="where">查询Lambda表达式</param>
/// <param name="number">获取的记录数量</param>
/// <returns></returns>
public IQueryable<T> FindList(Expression<Func<T, bool>> where, int number)
{
return DbContext.Set<T>().Where(where).Take(number);
}
/// <summary>
/// 查找实体列表
/// </summary>
/// <param name="where">查询Lambda表达式</param>
/// <param name="orderParam">排序参数</param>
/// <returns></returns>
public IQueryable<T> FindList(Expression<Func<T, bool>> where, OrderParam orderParam)
{
return FindList(where, orderParam, 0);
}
/// <summary>
/// 查找实体列表
/// </summary>
/// <param name="where">查询Lambda表达式</param>
/// <param name="orderParam">排序参数</param>
/// <param name="number">获取的记录数量【0-不启用】</param>
public IQueryable<T> FindList(Expression<Func<T, bool>> where, OrderParam orderParam, int number)
{
OrderParam[] _orderParams = null;
if (orderParam != null) _orderParams = new OrderParam[] { orderParam };
return FindList(where, _orderParams, number);
}
/// <summary>
/// 查找实体列表
/// </summary>
/// <param name="where">查询Lambda表达式</param>
/// <param name="orderParams">排序参数</param>
/// <param name="number">获取的记录数量【0-不启用】</param>
/// <returns></returns>
public IQueryable<T> FindList(Expression<Func<T, bool>> where, OrderParam[] orderParams, int number)
{
var _list = DbContext.Set<T>().Where(where);
var _orderParames = Expression.Parameter(typeof(T), "o");
if (orderParams != null && orderParams.Length > 0)
{
for (int i = 0; i < orderParams.Length; i++)
{
//根据属性名获取属性
var _property = typeof(T).GetProperty(orderParams[i].PropertyName);
//创建一个访问属性的表达式
var _propertyAccess = Expression.MakeMemberAccess(_orderParames, _property);
var _orderByExp = Expression.Lambda(_propertyAccess, _orderParames);
string _orderName = orderParams[i].Method == OrderMethod.ASC ? "OrderBy" : "OrderByDescending";
MethodCallExpression resultExp = Expression.Call(typeof(Queryable), _orderName, new Type[] { typeof(T), _property.PropertyType }, _list.Expression, Expression.Quote(_orderByExp));
_list = _list.Provider.CreateQuery<T>(resultExp);
}
}
if (number > 0) _list = _list.Take(number);
return _list;
}
#endregion
//查找实体分页列表
#region FindPageList
/// <summary>
/// 查找分页列表
/// </summary>
/// <param name="pageSize">每页记录数。必须大于1</param>
/// <param name="pageIndex">页码。首页从1开始，页码必须大于1</param>
/// <param name="totalNumber">总记录数</param>
/// <returns></returns>
public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber)
{
OrderParam _orderParam = null;
return FindPageList(pageSize, pageIndex, out totalNumber, _orderParam);
}
/// <summary>
/// 查找分页列表
/// </summary>
/// <param name="pageSize">每页记录数。必须大于1</param>
/// <param name="pageIndex">页码。首页从1开始，页码必须大于1</param>
/// <param name="totalNumber">总记录数</param>
/// <param name="order">排序键</param>
/// <param name="asc">是否正序</param>
/// <returns></returns>
public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber, OrderParam orderParam)
{
return FindPageList(pageSize, pageIndex, out totalNumber, (T) => true, orderParam);
}
/// <summary>
/// 查找分页列表
/// </summary>
/// <param name="pageSize">每页记录数。必须大于1</param>
/// <param name="pageIndex">页码。首页从1开始，页码必须大于1</param>
/// <param name="totalNumber">总记录数</param>
/// <param name="where">查询表达式</param>
public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber, Expression<Func<T, bool>> where)
{
OrderParam _param = null;
return FindPageList(pageSize, pageIndex, out totalNumber, where, _param);
}
/// <summary>
/// 查找分页列表
/// </summary>
/// <param name="pageSize">每页记录数。</param>
/// <param name="pageIndex">页码。首页从1开始</param>
/// <param name="totalNumber">总记录数</param>
/// <param name="where">查询表达式</param>
/// <param name="orderParam">排序【null-不设置】</param>
/// <returns></returns>
public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber, Expression<Func<T, bool>> where, OrderParam orderParam)
{
OrderParam[] _orderParams = null;
if (orderParam != null) _orderParams = new OrderParam[] { orderParam };
return FindPageList(pageSize, pageIndex, out totalNumber, where, _orderParams);
}
/// <summary>
/// 查找分页列表
/// </summary>
/// <param name="pageSize">每页记录数。</param>
/// <param name="pageIndex">页码。首页从1开始</param>
/// <param name="totalNumber">总记录数</param>
/// <param name="where">查询表达式</param>
/// <param name="orderParams">排序【null-不设置】</param>
public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber, Expression<Func<T, bool>> where, OrderParam[] orderParams)
{
if (pageIndex < 1) pageIndex = 1;
if (pageSize < 1) pageSize = 10;
IQueryable<T> _list = DbContext.Set<T>().Where(where);
var _orderParames = Expression.Parameter(typeof(T), "o");
if (orderParams != null && orderParams.Length > 0)
{
for (int i = 0; i < orderParams.Length; i++)
{
//根据属性名获取属性
var _property = typeof(T).GetProperty(orderParams[i].PropertyName);
//创建一个访问属性的表达式
var _propertyAccess = Expression.MakeMemberAccess(_orderParames, _property);
var _orderByExp = Expression.Lambda(_propertyAccess, _orderParames);
string _orderName = orderParams[i].Method == OrderMethod.ASC ? "OrderBy" : "OrderByDescending";
MethodCallExpression resultExp = Expression.Call(typeof(Queryable), _orderName, new Type[] { typeof(T), _property.PropertyType }, _list.Expression, Expression.Quote(_orderByExp));
_list = _list.Provider.CreateQuery<T>(resultExp);
}
}
totalNumber = _list.Count();
return _list.Skip((pageIndex - 1) * pageSize).Take(pageSize);
}
#endregion
//添加实体
#region Add
/// <summary>
/// 添加实体【立即保存】
/// </summary>
/// <param name="entity">实体</param>
/// <returns>受影响的对象的数目</returns>
public int Add(T entity)
{
return Add(entity, true);
}
/// <summary>
/// 添加实体
/// </summary>
/// <param name="entity">实体</param>
/// <param name="isSave">是否立即保存</param>
/// <returns>在“isSave”为True时返回受影响的对象的数目，为False时直接返回0</returns>
public int Add(T entity, bool isSave)
{
DbContext.Set<T>().Add(entity);
return isSave ? DbContext.SaveChanges() : 0;
}
#endregion
//更新实体
#region Update
/// <summary>
/// 更新实体【立即保存】
/// </summary>
/// <param name="entity">实体</param>
/// <returns>受影响的对象的数目</returns>
public int Update(T entity)
{
return Update(entity, true);
}
/// <summary>
/// 更新实体
/// </summary>
/// <param name="entity">实体</param>
/// <param name="isSave">是否立即保存</param>
/// <returns>在“isSave”为True时返回受影响的对象的数目，为False时直接返回0</returns>
public int Update(T entity, bool isSave)
{
DbContext.Set<T>().Attach(entity);
DbContext.Entry<T>(entity).State = EntityState.Modified;
return isSave ? DbContext.SaveChanges() : 0;
}
#endregion
//删除
#region Delete
/// <summary>
/// 删除实体【立即保存】
/// </summary>
/// <param name="entity">实体</param>
/// <returns>受影响的对象的数目</returns>
public int Delete(T entity)
{
return Delete(entity, true);
}
/// <summary>
/// 删除实体
/// </summary>
/// <param name="entity">实体</param>
/// <param name="isSave">是否立即保存</param>
/// <returns>在“isSave”为True时返回受影响的对象的数目，为False时直接返回0</returns>
public int Delete(T entity, bool isSave)
{
DbContext.Set<T>().Attach(entity);
DbContext.Entry<T>(entity).State = EntityState.Deleted;
return isSave ? DbContext.SaveChanges() : 0;
}
/// <summary>
/// 批量删除实体
/// </summary>
/// <param name="entities">实体集合</param>
/// <returns>受影响的对象的数目</returns>
public int Delete(IEnumerable<T> entities)
{
DbContext.Set<T>().RemoveRange(entities);
return DbContext.SaveChanges();
}
#endregion
//记录数
#region Count
/// <summary>
/// 记录数
/// </summary>
/// <returns></returns>
public int Count()
{
return DbContext.Set<T>().Count();
}
/// <summary>
/// 记录数
/// </summary>
/// <param name="predicate">表达式</param>
/// <returns></returns>
public int Count(Expression<Func<T, bool>> predicate)
{
return DbContext.Set<T>().Count(predicate);
}
#endregion
/// <summary>
/// 记录是否存在
/// </summary>
/// <param name="predicate">表达式</param>
/// <returns></returns>
public bool IsContains(Expression<Func<T, bool>> predicate)
{
return Count(predicate) > 0;
}
/// <summary>
/// 保存数据【在Add、Upate、Delete未立即保存的情况下使用】
/// </summary>
/// <returns>受影响的记录数</returns>
public int Save()
{
return DbContext.SaveChanges();
}
}
OrderParam辅助类
/// <summary>
/// 排序参数
/// </summary>
public class OrderParam
{
/// <summary>
/// 属性名
/// </summary>
public string PropertyName { get; set; }
/// <summary>
/// 排序方式
/// </summary>
public OrderMethod Method { get; set; }
}
/// <summary>
/// 排序方式
/// </summary>
public enum OrderMethod
{
/// <summary>
/// 正序
/// </summary>
ASC,
/// <summary>
/// 倒序
/// </summary>
DESC
}
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