分类:
随笔
常用方法封装：
public class DBHelper<T> where T : class
{
AproSysEntities context = new AproSysEntities();
/// <summary>
/// 新增一个实体
/// </summary>
/// <param name="entity"></param>
/// <returns></returns>
public int Add(T entity)
{
context.Entry<T>(entity).State = System.Data.EntityState.Added;
return context.SaveChanges();
}
/// <summary>
/// 删除一个实体
/// </summary>
/// <param name="entity"></param>
/// <returns></returns>
public int Remove(T entity)
{
context.Entry<T>(entity).State = System.Data.EntityState.Deleted;
return context.SaveChanges();
}
/// <summary>
/// 修改一个实体
/// </summary>
/// <param name="entity"></param>
/// <returns></returns>
public int Update(T entity)
{
context.Entry<T>(entity).State = System.Data.EntityState.Modified;
return context.SaveChanges();
}
/// <summary>
/// 批量新增实体
/// </summary>
/// <param name="dbContext"></param>
/// <returns></returns>
public int AddList(params T[] entities)
{
int result = 0;
for (int i = 0; i < entities.Count(); i++)
{
if (entities[i] == null)
continue;
context.Entry<T>(entities[i]).State = System.Data.EntityState.Added;
if (i != 0 && i % 20 == 0)
{
result += context.SaveChanges();
}
}
if (entities.Count() > 0)
result += context.SaveChanges();
return result;
}
/// <summary>
/// 批量删除实体
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public int RemoveList(Expression<Func<T, bool>> where)
{
var temp = context.Set<T>().Where(where);
foreach (var item in temp)
{
context.Entry<T>(item).State = System.Data.EntityState.Deleted;
}
return context.SaveChanges();
}
/// <summary>
/// 按条件查询
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public IQueryable<T> FindList(Expression<Func<T, bool>> where)
{
var temp = context.Set<T>().Where(where);
return temp;
}
/// <summary>
/// 按条件查询，排序
/// </summary>
/// <typeparam name="S"><peparam>
/// <param name="where"></param>
/// <param name="orderBy"></param>
/// <param name="isAsc"></param>
/// <returns></returns>
public IQueryable<T> FindList<S>(Expression<Func<T, bool>> where, Expression<Func<T, S>> orderBy, bool isAsc)
{
var list = context.Set<T>().Where(where);
if (isAsc)
list = list.OrderBy<T, S>(orderBy);
else
list = list.OrderByDescending<T, S>(orderBy);
return list;
}
/// <summary>
/// 按条件查询，分页
/// </summary>
/// <param name="pageIndex"></param>
/// <param name="pageSize"></param>
/// <param name="rowCount"></param>
/// <param name="where"></param>
/// <returns></returns>
public IQueryable<T> FindPagedList(int pageIndex, int pageSize, out int rowCount, Expression<Func<T, bool>> where)
{
var list = context.Set<T>().Where(where);
rowCount = list.Count();
list = list.Skip(pageSize * (pageIndex - 1)).Take(pageSize);
return list;
}
/// <summary>
/// 按条件查询，分页，排序
/// </summary>
/// <typeparam name="S"><peparam>
/// <param name="pageIndex"></param>
/// <param name="pageSize"></param>
/// <param name="rowCount"></param>
/// <param name="where"></param>
/// <param name="orderBy"></param>
/// <param name="isAsc"></param>
/// <returns></returns>
public IQueryable<T> FindPagedList<S>(int pageIndex, int pageSize, out int rowCount, Expression<Func<T, bool>> where, Expression<Func<T, S>> orderBy, bool isAsc)
{
var list = context.Set<T>().Where(where);
rowCount = list.Count();
if (isAsc)
list = list.OrderBy<T, S>(orderBy).Skip(pageSize * (pageIndex - 1)).Take(pageSize);
else
list = list.OrderByDescending<T, S>(orderBy).Skip(pageSize * (pageIndex - 1)).Take(pageSize);
return list;
}
}评价
