用Linq To SQL 搭建底层

用Linq To SQL 搭建底层

接口

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Linq.Expressions;

namespace Project.DAL
{
    interface IBaseService<T> where T:class,new()
    {
        IQueryable<T> QueryAll(params Expression<Func<T, bool>>[] where);
        IQueryable<T> QueryAll<type>(Expression<Func<T, type>> order, bool isAsc = true, params Expression<Func<T, bool>>[] where);
        IQueryable<T> QueryAll<type>(out int total, int skip = 0, int take = 10, Expression<Func<T, type>> order = null, bool isAsc = true, params Expression<Func<T, bool>>[] where);
        void Insert(T t);
        void Insert(IEnumerable<T> t);
        void Delete(T t);
        void Delete(IEnumerable<T> t);
        bool SaveChange();
    }
}

底层

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Linq.Expressions;

namespace Project.DAL
{
public class BaseService : IBaseService where T : class, new()
{
//上下文对象
Models.QuestionDBDataContext dbContext = new Models.QuestionDBDataContext();//直接复制会报错应先在Models里引入数据库

private IQueryable table = null;
private IQueryable GetTable()
{
if (table == null)
{
table = (IQueryable)dbContext.GetTable();
}
return table;
}

///

/// 查询
///

/// 查询条件
///
public IQueryable QueryAll(params Expression<Func<T, bool>>[] where)
{
IQueryable iq = GetTable();
if (where != null || where.Length < 1)
{
foreach (var item in where)
{
iq = iq.Where(item);
}
}
return iq;
}

///

/// 排序
///

/// 排序类型
/// 排序列
/// 升序or降序
///
///
public IQueryable QueryAll(Expression<Func<T, type>> order, bool isAsc = true, params Expression<Func<T, bool>>[] where)
{
var iq = QueryAll(where);
if (isAsc)
{
iq = iq.OrderBy(order);
}
else
{
iq = iq.OrderByDescending(order);
}
return iq;
}

///

/// 分页查询
///

///
/// 总数据数
/// 跳过n条
/// 取n条（一页显示几条）
///
///
///
///
public IQueryable QueryAll(out int total, int skip = 0, int take = 10, Expression<Func<T, type>> order = null, bool isAsc = true, params Expression<Func<T, bool>>[] where)
{
var iq = QueryAll(order, isAsc, where);
total = iq.Count();
return iq.Skip(skip).Take(take);
}

public void Insert(T t)
{
dbContext.GetTable().InsertOnSubmit(t);
}

public void Insert(IEnumerable t)
{
dbContext.GetTable().InsertAllOnSubmit(t);
}

public void Delete(T t)
{
dbContext.GetTable().DeleteOnSubmit(t);
}

public void Delete(IEnumerable t)
{
dbContext.GetTable().DeleteAllOnSubmit(t);
}

///

/// 保存修改
///

///
public bool SaveChange()
{
try
{
dbContext.SubmitChanges();
return true;
}
catch (Exception e)
{
return false;
}
}
}
}