ASP.NET MVC5網(wǎng)站開(kāi)發(fā)之實(shí)現(xiàn)數(shù)據(jù)存儲(chǔ)層功能(三)

更新時(shí)間：2022年05月08日 14:27:58 作者：洞庭夕照

這篇文章主要為大家詳細(xì)介紹了ASP.NET MVC5網(wǎng)站開(kāi)發(fā)之實(shí)現(xiàn)數(shù)據(jù)存儲(chǔ)層功能，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

數(shù)據(jù)存儲(chǔ)層在項(xiàng)目Ninesky.DataLibrary中實(shí)現(xiàn)，整個(gè)項(xiàng)目只有一個(gè)類(lèi)Repository。

Repository中實(shí)現(xiàn)增刪改查詢(xún)等方法供業(yè)務(wù)邏輯層調(diào)用，主要功能如下圖：

具體步驟

一、添加實(shí)體框架的引用

1、打開(kāi)解決方案，選擇項(xiàng)目Ninesky.DataLibrary，在引用上右鍵，選擇管理NuGet程序包。

在NuGet包管理器中的瀏覽標(biāo)簽中點(diǎn)擊EntityFramework，點(diǎn)擊右側(cè)欄的安裝按鈕。

在搜索框輸入EntityFramework.zh-Hans,安裝假體中文資源包。

二、實(shí)現(xiàn)數(shù)據(jù)倉(cāng)儲(chǔ)類(lèi)

打開(kāi)解決方案，選擇項(xiàng)目Ninesky.DataLibrary，將Class1.cs重命名為Repository.cs，在文檔頭添加using System.Data.Entity;將類(lèi)名重命名為public class Repository。改為public class Repository<T> where T :class

1、DbContext屬性

在Repository類(lèi)中添加如下代碼 public DbContext DbContext { get; set; }

2、構(gòu)造函數(shù)

為類(lèi)中添加夠高函數(shù)，可以直接傳遞DbContex。

public Repository()
    { }
    public Repository(DbContext dbContext)
    {
      DbContext = dbContext;
    }

3、查找實(shí)體方法Find

Find有一個(gè)重載。兩個(gè)方法分別可以根據(jù)ID和根據(jù)lamdba表達(dá)式查找實(shí)體。

/// <summary>
    /// 查找實(shí)體
    /// </summary>
    /// <param name="ID">實(shí)體主鍵值</param>
    /// <returns></returns>
    public T Find(int ID)
    {
      return DbContext.Set<T>().Find(ID);
    }

    /// <summary>
    /// 查找實(shí)體
    /// </summary>
    /// <param name="where">查詢(xún)Lambda表達(dá)式</param>
    /// <returns></returns>
    public T Find(Expression<Func<T,bool>> where)
    {
      return DbContext.Set<T>().SingleOrDefault(where);
    }

4、查找實(shí)體列表方法FindList

根據(jù)需要FindList進(jìn)行多次重載

/// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <returns></returns>
    public IQueryable<T> FindList()
    {
      return DbContext.Set<T>();
    }

    /// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <typeparam name="TKey">排序建類(lèi)型</typeparam>
    /// <param name="order">排序表達(dá)式</param>
    /// <param name="asc">是否正序</param>
    /// <returns></returns>
    public IQueryable<T> FindList<TKey>(Expression<Func<T, TKey>> order, bool asc)
    {
      return asc ? DbContext.Set<T>().OrderBy(order) : DbContext.Set<T>().OrderByDescending(order);
    }

    /// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <typeparam name="TKey">排序鍵類(lèi)型</typeparam>
    /// <param name="order">排序鍵</param>
    /// <param name="asc">是否正序</param>
    /// <param name="number">獲取的記錄數(shù)量</param>
    /// <returns></returns>
    public IQueryable<T> FindList<TKey>(Expression<Func<T, TKey>> order, bool asc,int number)
    {
      return asc ? DbContext.Set<T>().OrderBy(order).Take(number) : DbContext.Set<T>().OrderByDescending(order).Take(number);
    }

    /// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <param name="where">查詢(xún)Lambda表達(dá)式</param>
    /// <returns></returns>
    public IQueryable<T> FindList(Expression<Func<T, bool>> where)
    {
      return DbContext.Set<T>().Where(where);
    }

    /// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <param name="where">查詢(xún)Lambda表達(dá)式</param>
    /// <param name="number">獲取的記錄數(shù)量</param>
    /// <returns></returns>
    public IQueryable<T> FindList(Expression<Func<T, bool>> where, int number)
    {
      return DbContext.Set<T>().Where(where).Take(number);
    }

    /// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <typeparam name="TKey">排序鍵類(lèi)型</typeparam>
    /// <param name="where">查詢(xún)Lambda表達(dá)式</param>
    /// <param name="order">排序鍵</param>
    /// <param name="asc">是否正序</param>
    /// <returns></returns>
    public IQueryable<T> FindList<TKey>(Expression<Func<T, bool>> where, Expression<Func<T, TKey>> order, bool asc)
    {
      return asc ? DbContext.Set<T>().Where(where).OrderBy(order) : DbContext.Set<T>().Where(where).OrderByDescending(order);
    }

    /// <summary>
    /// 查找實(shí)體列表
    /// </summary>
    /// <typeparam name="TKey">排序鍵類(lèi)型</typeparam>
    /// <param name="where">查詢(xún)Lambda表達(dá)式</param>
    /// <param name="order">排序鍵</param>
    /// <param name="asc">是否正序</param>
    /// <param name="number">獲取的記錄數(shù)量</param>
    /// <returns></returns>
    public IQueryable<T> FindList<TKey>(Expression<Func<T, bool>> where, Expression<Func<T, TKey>> order, bool asc, int number)
    {
      return asc ? DbContext.Set<T>().Where(where).OrderBy(order).Take(number) : DbContext.Set<T>().Where(where).OrderByDescending(order).Take(number);
    }

5、查找實(shí)體分頁(yè)列表方法FindPageList

根據(jù)需要FindPageList進(jìn)行多次重載

/// <summary>
    /// 查找分頁(yè)列表
    /// </summary>
    /// <param name="pageSize">每頁(yè)記錄數(shù)。必須大于1</param>
    /// <param name="pageIndex">頁(yè)碼。首頁(yè)從1開(kāi)始，頁(yè)碼必須大于1</param>
    /// <param name="totalNumber">總記錄數(shù)</param>
    /// <returns></returns>
    public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber)
    {
      if (pageIndex < 1) pageIndex = 1;
      if (pageSize < 1) pageSize = 10;
      IQueryable<T> _list = DbContext.Set<T>();
      totalNumber = _list.Count();
      return _list.Skip((pageIndex - 1) * pageIndex).Take(pageSize);
    }

    /// <summary>
    /// 查找分頁(yè)列表
    /// </summary>
    /// <param name="pageSize">每頁(yè)記錄數(shù)。必須大于1</param>
    /// <param name="pageIndex">頁(yè)碼。首頁(yè)從1開(kāi)始，頁(yè)碼必須大于1</param>
    /// <param name="totalNumber">總記錄數(shù)</param>
    /// <param name="order">排序鍵</param>
    /// <param name="asc">是否正序</param>
    /// <returns></returns>
    public IQueryable<T> FindPageList<TKey>(int pageSize, int pageIndex, out int totalNumber, Expression<Func<T, TKey>> order, bool asc)
    {
      if (pageIndex < 1) pageIndex = 1;
      if (pageSize < 1) pageSize = 10;
      IQueryable<T> _list = DbContext.Set<T>();
      _list = asc ? _list.OrderBy(order) : _list.OrderByDescending(order);
      totalNumber = _list.Count();
      return _list.Skip((pageIndex - 1) * pageIndex).Take(pageSize);
    }

    /// <summary>
    /// 查找分頁(yè)列表
    /// </summary>
    /// <param name="pageSize">每頁(yè)記錄數(shù)。必須大于1</param>
    /// <param name="pageIndex">頁(yè)碼。首頁(yè)從1開(kāi)始，頁(yè)碼必須大于1</param>
    /// <param name="totalNumber">總記錄數(shù)</param>
    /// <param name="where">查詢(xún)表達(dá)式</param>
    public IQueryable<T> FindPageList(int pageSize, int pageIndex, out int totalNumber, Expression<Func<T, bool>> where)
    {
      if (pageIndex < 1) pageIndex = 1;
      if (pageSize < 1) pageSize = 10;
      IQueryable<T> _list = DbContext.Set<T>().Where(where);
      totalNumber = _list.Count();
      return _list.Skip((pageIndex - 1) * pageIndex).Take(pageSize);
    }

    /// <summary>
    /// 查找分頁(yè)列表
    /// </summary>
    /// <param name="pageSize">每頁(yè)記錄數(shù)。必須大于1</param>
    /// <param name="pageIndex">頁(yè)碼。首頁(yè)從1開(kāi)始，頁(yè)碼必須大于1</param>
    /// <param name="totalNumber">總記錄數(shù)</param>
    /// <param name="where">查詢(xún)表達(dá)式</param>
    /// <param name="order">排序鍵</param>
    /// <param name="asc">是否正序</param>
    public IQueryable<T> FindPageList<TKey>(int pageSize, int pageIndex, out int totalNumber, Expression<Func<T, bool>> where, Expression<Func<T, TKey>> order, bool asc)
    {
      if (pageIndex < 1) pageIndex = 1;
      if (pageSize < 1) pageSize = 10;
      IQueryable<T> _list = DbContext.Set<T>().Where(where);
      _list = asc ? _list.OrderBy(order) : _list.OrderByDescending(order);
      totalNumber = _list.Count();
      return _list.Skip((pageIndex - 1) * pageIndex).Take(pageSize);
    }

6、添加實(shí)體方法Add

Add 方法有一個(gè)重載，重載方法可以選擇是否立即保存

/// <summary>
    /// 添加實(shí)體
    /// </summary>
    /// <param name="entity">實(shí)體</param>
    /// <returns>受影響的對(duì)象的數(shù)目</returns>
    public int Add(T entity)
    {
      return Add(entity, true);
    }

    /// <summary>
    /// 添加實(shí)體
    /// </summary>
    /// <param name="entity">實(shí)體</param>
    /// <param name="isSave">是否立即保存</param>
    /// <returns>在“isSave”為T(mén)rue時(shí)返回受影響的對(duì)象的數(shù)目，為False時(shí)直接返回0</returns>
    public int Add(T entity,bool isSave)
    {
      DbContext.Set<T>().Add(entity);
      return isSave ? DbContext.SaveChanges() : 0;
    }

7、更新實(shí)體方法Update

Updae 方法有一個(gè)重載，重載方法可以選擇是否立即保存

#region Update

    /// <summary>
    /// 更新實(shí)體【立即保存】
    /// </summary>
    /// <param name="entity">實(shí)體</param>
    /// <returns>在“isSave”為T(mén)rue時(shí)返回受影響的對(duì)象的數(shù)目，為False時(shí)直接返回0</returns>
    public int Update(T entity)
    {
      return Update(entity, true);
    }

    /// <summary>
    /// 更新實(shí)體
    /// </summary>
    /// <param name="entity">實(shí)體</param>
    /// <param name="isSave">是否立即保存</param>
    /// <returns>在“isSave”為T(mén)rue時(shí)返回受影響的對(duì)象的數(shù)目，為False時(shí)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;
    }

8、刪除實(shí)體方法Delete

Delete 方法有兩個(gè)重載，一個(gè)是可以選擇否立即保存，另一個(gè)是批量刪除

/// <summary>
    /// 刪除實(shí)體【立即保存】
    /// </summary>
    /// <param name="entity">實(shí)體</param>
    /// <returns>受影響的對(duì)象的數(shù)目</returns>
    public int Delete(T entity)
    {
      return Delete(entity, true);
    }

    /// <summary>
    /// 刪除實(shí)體
    /// </summary>
    /// <param name="entity">實(shí)體</param>
    /// <param name="isSave">是否立即保存</param>
    /// <returns>在“isSave”為T(mén)rue時(shí)返回受影響的對(duì)象的數(shù)目，為False時(shí)直接返回0</returns>
    public int Delete(T entity,bool isSave)
    {
      DbContext.Set<T>().Remove(entity);
      return isSave ? DbContext.SaveChanges() : 0;
    }

    /// <summary>
    /// 批量刪除實(shí)體
    /// </summary>
    /// <param name="entities">實(shí)體集合</param>
    /// <returns>受影響的對(duì)象的數(shù)目</returns>
    public int Delete(IEnumerable<T> entities)
    {
      DbContext.Set<T>().RemoveRange(entities);
      return DbContext.SaveChanges();
    }

9、統(tǒng)計(jì)記錄數(shù)方法Count

Count 方法有一個(gè)重載，可以根據(jù)表達(dá)式進(jìn)行統(tǒng)計(jì)

/// <summary>
    /// 記錄數(shù)
    /// </summary>
    /// <returns></returns>
    public int Count()
    {
      return DbContext.Set<T>().Count();
    }

    /// <summary>
    /// 記錄數(shù)
    /// </summary>
    /// <param name="predicate">表達(dá)式</param>
    /// <returns></returns>
    public int Count(Expression<Func<T, bool>> predicate)
    {
      return DbContext.Set<T>().Count(predicate);
    }

10、是否存在

/// <summary>
    /// 記錄是否存在
    /// </summary>
    /// <param name="predicate">表達(dá)式</param>
    /// <returns></returns>
    public bool IsContains(Expression<Func<T, bool>> predicate)
    {
      return Count(predicate) > 0;
    }

11、保存到數(shù)據(jù)庫(kù)

/// <summary>
    /// 保存數(shù)據(jù)【在A(yíng)dd、Upate、Delete未立即保存的情況下使用】
    /// </summary>
    /// <returns>受影響的記錄數(shù)</returns>
    public int Save()
    {
      return DbContext.SaveChanges();
    }

以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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