之前寫過關於實現一個完整的ＥＦ架構的文章，文章的閱讀量也是滿大的，自己很欣慰，但是，那篇文章是我２０１１年寫的，所以，技術有些不成熟，所以今天把我的２０１４年寫的EF底層架構公開一下，這個架構比２０１１年的有了很大程度的提高，主要在介面規範，查詢規範上，並引入了排序功能，兩步對完善了ＥＦ對資料的批量操作，可以說，這次的架構是很有看點的。
一 一個基礎操作介面
/// <summary> /// 基礎的資料操作規範 /// 與ＯＲＭ架構無關 /// </summary> /// <typeparam name="TEntity"></typeparam> public interface IRepository<TEntity> where TEntity : class { /// <summary> /// 設定資料上下文,它一般由構架方法注入 /// </summary> /// <param name="unitOfWork"></param> void SetDbContext(IUnitOfWork unitOfWork); /// <summary> /// 新增實體並提交到資料伺服器 /// </summary> /// <param name="item">Item to add to repository</param> void Insert(TEntity item); /// <summary> /// 移除實體並提交到資料伺服器 /// 如果表存在約束，需要先刪除子表資訊 /// </summary> /// <param name="item">Item to delete</param> void Delete(TEntity item); /// <summary> /// 修改實體並提交到資料伺服器 /// </summary> /// <param name="item"></param> void Update(TEntity item); /// <summary> /// 得到指定的實體集合（延時結果集） /// Get all elements of type {T} in repository /// </summary> /// <returns>List of selected elements</returns> IQueryable<TEntity> GetModel(); /// <summary> /// 根據主鍵得到實體 /// </summary> /// <param name="id"></param> /// <returns></returns> TEntity Find(params object[] id); }
二 一個擴充套件操作介面
/// <summary> /// 擴充套件的Repository操作規範 /// </summary> public interface IExtensionRepository<TEntity> : IRepository<TEntity>, IOrderableRepository<TEntity> where TEntity : class { /// <summary> /// 新增集合[集合數目不大時用此方法，超大集合使用BulkInsert] /// </summary> /// <param name="item"></param> void Insert(IEnumerable<TEntity> item); /// <summary> /// 修改集合[集合數目不大時用此方法，超大集合使用BulkUpdate] /// </summary> /// <param name="item"></param> void Update(IEnumerable<TEntity> item); /// <summary> /// 刪除集合[集合數目不大時用此方法，超大集合使用批量刪除] /// </summary> /// <param name="item"></param> void Delete(IEnumerable<TEntity> item); /// <summary> /// 擴充套件更新方法，只對EF支援 /// 注意本方法不能和GetModel()一起使用，它的表主鍵可以通過post或get方式獲取 /// </summary> /// <param name="entity"></param> void Update<T>(Expression<Action<T>> entity) where T : class; /// <summary> /// 根據指定lambda表示式,得到延時結果集 /// </summary> /// <param name="predicate"></param> /// <returns></returns> IQueryable<TEntity> GetModel(Expression<Func<TEntity, bool>> predicate); /// <summary> /// 根據指定lambda表示式,得到第一個實體 /// </summary> /// <param name="predicate"></param> /// <returns></returns> TEntity Find(Expression<Func<TEntity, bool>> predicate); /// <summary> /// 批量新增，新增之前可以去除自增屬性,預設不去除 /// </summary> /// <param name="item"></param> /// <param name="isRemoveIdentity"></param> void BulkInsert(IEnumerable<TEntity> item, bool isRemoveIdentity); /// <summary> /// 批量新增 /// </summary> /// <param name="item"></param> void BulkInsert(IEnumerable<TEntity> item); /// <summary> /// 批量更新 /// </summary> /// <param name="item"></param> void BulkUpdate(IEnumerable<TEntity> item, params string[] fieldParams); /// <summary> /// 批量刪除 /// </summary> /// <param name="item"></param> void BulkDelete(IEnumerable<TEntity> item); }
三 一個排序操作介面
/// <summary> /// 提供排序功能的規範 /// </summary> public interface IOrderableRepository<TEntity> where TEntity : class { /// <summary> /// 帶排序的結果集 /// </summary> /// <param name="orderBy"></param> /// <returns></returns> IQueryable<TEntity> GetModel(Action<IOrderable<TEntity>> orderBy); /// <summary> /// 根據指定lambda表示式和排序方式,得到延時結果集 /// </summary> /// <param name="predicate"></param> /// <returns></returns> IQueryable<TEntity> GetModel(Action<IOrderable<TEntity>> orderBy, Expression<Func<TEntity, bool>> predicate); }
四 基於ef架構的規約查詢介面
/// <summary> /// EF底層構架，關於規約功能的倉儲介面 /// </summary> /// <typeparam name="TEntity"></typeparam> public interface ISpecificationRepository<TEntity> : IExtensionRepository<TEntity> where TEntity : class { /// <summary> /// 根據指定規約,得到延時結果集 /// </summary> /// <param name="specification"></param> /// <returns></returns> IQueryable<TEntity> GetModel(ISpecification<TEntity> specification); /// <summary> /// 根據指定規約,得到第一個實體 /// </summary> /// <param name="specification"></param> /// <returns></returns> TEntity Find(ISpecification<TEntity> specification); /// <summary> /// 帶排序功能的，根據指定規約，得到結果集 /// </summary> /// <param name="orderBy"></param> /// <param name="specification"></param> /// <returns></returns> IQueryable<TEntity> GetModel(Action<IOrderable<TEntity>> orderBy, EntityFrameworks.Entity.Core.Specification.ISpecification<TEntity> specification); /// <summary> /// 儲存之後觸發 /// Occurs after data saved /// </summary> event Action<SavedEventArgs> AfterSaved; /// <summary> /// 儲存之前觸發 /// Occurs before data saved /// </summary> event Action<SavedEventArgs> BeforeSaved; }
五 基於工作單元的標識介面
/// <summary> /// 資料上下文標識介面，它對於業務層應該是公開的 /// 它對於實現上下文的方法，它並不關心，可以是linq2sql,ef,ado.net,nhibernate,memory,nosql等 /// </summary> public interface IUnitOfWork { }
六 基於ef的DbContext上下文的倉儲的實現
/// <summary> /// DbContext上下文倉儲功能類，領域上下文可以直接繼承它 /// 生命週期：資料上下文的生命週期為一個HTTP請求的結束 /// 相關說明： /// 1 領域物件使用宣告IRepository和IExtensionRepository介面得到不同的操作規範 /// 2 可以直接為上下注入Action<string>的委託例項，用來記錄savechanges產生的異常 /// 3 可以訂閱BeforeSaved和AfterSaved兩個事件，用來在方法提交前與提交後實現程式碼注入 /// 4 所有領域db上下文都要繼承iUnitWork介面，用來實現工作單元，這對於提升程式效能與為重要 /// </summary> /// <typeparam name="TEntity"></typeparam> public class DbContextRepository<TEntity> : ISpecificationRepository<TEntity> where TEntity : class { #region Constructors public DbContextRepository(IUnitOfWork db, Action<string> logger) { UnitWork = db; Db = (DbContext)db; Logger = logger; ((IObjectContextAdapter)Db).ObjectContext.CommandTimeout = 0; } public DbContextRepository(IUnitOfWork db) : this(db, null) { } #endregion #region Properties /// <summary> /// 資料上下文 /// </summary> protected DbContext Db { get; private set; } /// <summary> /// 工作單元上下文,子類可以直接使用它 /// </summary> protected IUnitOfWork UnitWork { get; set; } /// <summary> /// Action委託事例，在派生類可以操作它 /// </summary> protected Action<string> Logger { get; private set; } #endregion #region Fields /// <summary> /// 資料總數 /// </summary> int _dataTotalCount = 0; /// <summary> /// 資料總頁數 /// </summary> int _dataTotalPages = 0; /// <summary> /// 資料頁面大小（每次向資料庫提交的記錄數） /// </summary> private const int DataPageSize = 10000; #endregion #region Delegates & Event /// <summary> /// 儲存之後 /// </summary> public event Action<SavedEventArgs> AfterSaved; /// <summary> /// 儲存之前 /// </summary> public event Action<SavedEventArgs> BeforeSaved; #endregion #region IRepository<TEntity> 成員 public void SetDbContext(IUnitOfWork unitOfWork) { this.Db = (DbContext)unitOfWork; this.UnitWork = unitOfWork; } public virtual void Insert(TEntity item) { OnBeforeSaved(new SavedEventArgs(item, SaveAction.Insert)); Db.Entry<TEntity>(item); Db.Set<TEntity>().Add(item); this.SaveChanges(); OnAfterSaved(new SavedEventArgs(item, SaveAction.Insert)); } public virtual void Delete(TEntity item) { OnBeforeSaved(new SavedEventArgs(item, SaveAction.Delete)); Db.Set<TEntity>().Attach(item); Db.Set<TEntity>().Remove(item); this.SaveChanges(); OnAfterSaved(new SavedEventArgs(item, SaveAction.Delete)); } public virtual void Update(TEntity item) { OnBeforeSaved(new SavedEventArgs(item, SaveAction.Update)); Db.Set<TEntity>().Attach(item); Db.Entry(item).State = EntityState.Modified; try { this.SaveChanges(); } catch (System.Data.OptimisticConcurrencyException ex)//併發衝突異常 { ((IObjectContextAdapter)Db).ObjectContext.Refresh(RefreshMode.ClientWins, item); this.SaveChanges(); } OnAfterSaved(new SavedEventArgs(item, SaveAction.Update)); } /// <summary> /// 子類在實現時，可以重寫，加一些狀態過濾 /// </summary> /// <returns></returns> public virtual IQueryable<TEntity> GetModel() { // return Db.Set<TEntity>().AsNoTracking();//物件無法自動新增到上下文中，因為它是使用 NoTracking 合併選項檢索的。請在定義此關係之前，將該實體顯式附加到 ObjectContext。 return Db.Set<TEntity>();////ObjectStateManager 中已存在具有同一鍵的物件。ObjectStateManager 無法跟蹤具有相同鍵的多個物件。 } /// <summary> /// 得到原生態結果集 /// </summary> /// <returns></returns> public IQueryable<TEntity> GetEntities() { return Db.Set<TEntity>(); } #endregion #region IExtensionRepository<TEntity> 成員 public virtual void Insert(IEnumerable<TEntity> item) { item.ToList().ForEach(i => { Db.Entry<TEntity>(i); Db.Set<TEntity>().Add(i); }); this.SaveChanges(); } public virtual void Delete(IEnumerable<TEntity> item) { item.ToList().ForEach(i => { Db.Set<TEntity>().Attach(i); Db.Set<TEntity>().Remove(i); }); this.SaveChanges(); } public virtual void Update(IEnumerable<TEntity> item) { item.ToList().ForEach(i => { Db.Set<TEntity>().Attach(i); Db.Entry(i).State = EntityState.Modified; }); try { this.SaveChanges(); } catch (System.Data.OptimisticConcurrencyException ex)//併發衝突異常 { ((IObjectContextAdapter)Db).ObjectContext.Refresh(RefreshMode.ClientWins, item); this.SaveChanges(); } } public void Update<T>(Expression<Action<T>> entity) where T : class { T newEntity = typeof(T).GetConstructor(Type.EmptyTypes).Invoke(null) as T;//建立指定型別的例項 List<string> propertyNameList = new List<string>(); MemberInitExpression param = entity.Body as MemberInitExpression; foreach (var item in param.Bindings) { string propertyName = item.Member.Name; object propertyValue; var memberAssignment = item as MemberAssignment; if (memberAssignment.Expression.NodeType == ExpressionType.Constant) { propertyValue = (memberAssignment.Expression as ConstantExpression).Value; } else { propertyValue = Expression.Lambda(memberAssignment.Expression, null).Compile().DynamicInvoke(); } typeof(T).GetProperty(propertyName).SetValue(newEntity, propertyValue, null); propertyNameList.Add(propertyName); } try { Db.Set<T>().Attach(newEntity); } catch (Exception) { throw new Exception("本方法不能和GetModel()一起使用，請使用Update(TEntity entity)方法"); } Db.Configuration.ValidateOnSaveEnabled = false; var ObjectStateEntry = ((IObjectContextAdapter)Db).ObjectContext.ObjectStateManager.GetObjectStateEntry(newEntity); propertyNameList.ForEach(x => ObjectStateEntry.SetModifiedProperty(x.Trim())); try { this.SaveChanges(); } catch (System.Data.OptimisticConcurrencyException ex)//併發衝突異常 { ((IObjectContextAdapter)Db).ObjectContext.Refresh(RefreshMode.ClientWins, newEntity); this.SaveChanges(); } } public TEntity Find(params object[] id) { return Db.Set<TEntity>().Find(id); } public IQueryable<TEntity> GetModel(Expression<Func<TEntity, bool>> predicate) { return GetModel().Where(predicate); } public TEntity Find(Expression<Func<TEntity, bool>> predicate) { return GetModel(predicate).FirstOrDefault(); } public void BulkInsert(IEnumerable<TEntity> item) { BulkInsert(item, false); } public void BulkInsert(IEnumerable<TEntity> item, bool isRemoveIdentity) { string startTag = "", endTag = ""; if (isRemoveIdentity) { startTag = "SET IDENTITY_INSERT " + typeof(TEntity).Name + " ON;"; endTag = "SET IDENTITY_INSERT " + typeof(TEntity).Name + " OFF;"; } DataPageProcess(item, (currentItems) => { ((IObjectContextAdapter)Db).ObjectContext.CommandTimeout = 0;//永不超時 Db.Database.ExecuteSqlCommand(startTag + DoSql(currentItems, SqlType.Insert) + endTag); }); } public void BulkDelete(IEnumerable<TEntity> item) { DataPageProcess(item, (currentItems) => { ((IObjectContextAdapter)Db).ObjectContext.CommandTimeout = 0;//永不超時 Db.Database.ExecuteSqlCommand(DoSql(currentItems, SqlType.Delete)); }); } public void BulkUpdate(IEnumerable<TEntity> item, params string[] fieldParams) { DataPageProcess(item, (currentItems) => { ((IObjectContextAdapter)Db).ObjectContext.CommandTimeout = 0;//永不超時 Db.Database.ExecuteSqlCommand(DoSql(currentItems, SqlType.Update, fieldParams)); }); } #endregion #region ISpecificationRepository<TEntity> 成員 public TEntity Find(ISpecification<TEntity> specification) { return GetModel(specification).FirstOrDefault(); } public IQueryable<TEntity> GetModel(Action<IOrderable<TEntity>> orderBy, ISpecification<TEntity> specification) { var linq = new Orderable<TEntity>(GetModel(specification)); orderBy(linq); return linq.Queryable; } public IQueryable<TEntity> GetModel(ISpecification<TEntity> specification) { return GetModel().Where(specification.SatisfiedBy()); } #endregion #region IOrderableRepository<TEntity>成員 public IQueryable<TEntity> GetModel(Action<IOrderable<TEntity>> orderBy) { var linq = new Orderable<TEntity>(GetModel()); orderBy(linq); return linq.Queryable; } public IQueryable<TEntity> GetModel(Action<IOrderable<TEntity>> orderBy, Expression<Func<TEntity, bool>> predicate) { var linq = new Orderable<TEntity>(GetModel(predicate)); orderBy(linq); return linq.Queryable; } #endregion #region Protected Methods /// <summary> /// 根據工作單元的IsNotSubmit的屬性，去判斷是否提交到資料庫 /// 一般地，在多個repository型別進行組合時，這個IsNotSubmit都會設為true，即不馬上提交， /// 而對於單個repository操作來說，它的值不需要設定，使用預設的false，將直接提交到資料庫，這也保證了操作的原子性。 /// </summary> protected void SaveChanges() { try { Db.SaveChanges(); } catch (System.Data.Entity.Validation.DbEntityValidationException dbEx)//捕獲實體驗證異常 { var sb = new StringBuilder(); dbEx.EntityValidationErrors.First().ValidationErrors.ToList().ForEach(i => { sb.AppendFormat("屬性為：{0}，資訊為：{1}\n\r", i.PropertyName, i.ErrorMessage); }); if (Logger == null) throw new Exception(sb.ToString()); Logger(sb.ToString() + "處理時間：" + DateTime.Now); } catch (System.Data.OptimisticConcurrencyException ex)//併發衝突異常 { //保持資料來源中物件的現有屬性 //Db.Refresh(RefreshMode.StoreWins, person); // Db.SaveChanges(); } catch (Exception ex)//捕獲所有異常 { if (Logger == null)//如果沒有定義日誌功能，就把異常丟擲來吧 throw new Exception(ex.Message); Logger(ex.Message + "處理時間：" + DateTime.Now); } } /// <summary> /// 計數更新,與SaveChange()是兩個SQL連結，走分散式事務 /// 子類可以根據自己的邏輯，去複寫 /// tableName:表名 /// param:索引0為主鍵名，1表主鍵值，2為要計數的欄位，3為增量 /// </summary> /// <param name="tableName">表名</param> /// <param name="param">引數列表，索引0為主鍵名，1表主鍵值，2為要計數的欄位，3為增量</param> protected virtual void UpdateForCount(string tableName, params object[] param) { string sql = "update [" + tableName + "] set [{2}]=ISNULL([{2}],0)+{3} where [{0}]={1}"; var listParasm = new List<object> { param[0], param[1], param[2], param[3], }; Db.Database.ExecuteSqlCommand(string.Format(sql, listParasm.ToArray())); } #endregion #region Virtual Methods /// <summary> /// Called after data saved /// </summary> /// <param name="e"></param> protected virtual void OnAfterSaved(SavedEventArgs e) { if (AfterSaved != null) { AfterSaved(e); } } /// <summary> /// Called before saved /// </summary> /// <param name="e"></param> protected virtual void OnBeforeSaved(SavedEventArgs e) { if (BeforeSaved != null) { BeforeSaved(e); } } #endregion #region Private Methods /// <summary> /// 分頁進行資料提交的邏輯 /// </summary> /// <param name="item">原列表</param> /// <param name="method">處理方法</param> /// <param name="currentItem">要進行處理的新列表</param> private void DataPageProcess(IEnumerable<TEntity> item, Action<IEnumerable<TEntity>> method) { if (item != null && item.Any()) { _dataTotalCount = item.Count(); this._dataTotalPages = item.Count() / DataPageSize; if (_dataTotalCount % DataPageSize > 0) _dataTotalPages += 1; for (int pageIndex = 1; pageIndex <= _dataTotalPages; pageIndex++) { var currentItems = item.Skip((pageIndex - 1) * DataPageSize).Take(DataPageSize).ToList(); method(currentItems); } } } private static string GetEqualStatment(string fieldName, int paramId, Type pkType) { if (pkType.IsValueType) return string.Format("{0} = {1}", fieldName, GetParamTag(paramId)); return string.Format("{0} = '{1}'", fieldName, GetParamTag(paramId)); } private static string GetParamTag(int paramId) { return "{" + paramId + "}"; } /// <summary> /// 得到實體鍵EntityKey /// </summary> /// <typeparam name="TEntity"></typeparam> /// <returns></returns> protected ReadOnlyMetadataCollection<EdmMember> GetPrimaryKey() { EntitySetBase primaryKey = ((IObjectContextAdapter)Db).ObjectContext.GetEntitySet(typeof(TEntity)); if (primaryKey == null) return null; ReadOnlyMetadataCollection<EdmMember> arr = primaryKey.ElementType.KeyMembers; return arr; } /// <summary> /// 構建Update語句串 /// 注意：如果本方法過濾了int,decimal型別更新為０的列，如果希望更新它們需要指定FieldParams引數 /// </summary> /// <param name="entity">實體列表</param> /// <param name="fieldParams">要更新的欄位</param> /// <returns></returns> private Tuple<string, object[]> CreateUpdateSql(TEntity entity, params string[] fieldParams) { if (entity == null) throw new ArgumentException("The database entity can not be null."); var pkList = GetPrimaryKey().Select(i => i.Name).ToList(); var entityType = entity.GetType(); var tableFields = new List<PropertyInfo>(); if (fieldParams != null && fieldParams.Count() > 0) { tableFields = entityType.GetProperties().Where(i => fieldParams.Contains(i.Name, new StringComparisonIgnoreCase())).ToList(); } else { tableFields = entityType.GetProperties().Where(i => !pkList.Contains(i.Name) && i.GetValue(entity, null) != null && !i.PropertyType.IsEnum && !(i.PropertyType == typeof(ValueType) && Convert.ToInt64(i.GetValue(entity, null)) == 0) && !(i.PropertyType == typeof(DateTime) && Convert.ToDateTime(i.GetValue(entity, null)) == DateTime.MinValue) && i.PropertyType != typeof(EntityState) && i.GetCustomAttributes(false).Where(j => j.GetType() == typeof(NavigationAttribute)) != null//過濾導航屬性 && (i.PropertyType.IsValueType || i.PropertyType == typeof(string)) ).ToList(); } //過濾主鍵，航行屬性，狀態屬性等 if (pkList == null || pkList.Count == 0) throw new ArgumentException("The Table entity have not a primary key."); var arguments = new List<object>(); var builder = new StringBuilder(); foreach (var change in tableFields) { if (pkList.Contains(change.Name)) continue; if (arguments.Count != 0) builder.Append(", "); builder.Append(change.Name + " = {" + arguments.Count + "}"); if (change.PropertyType == typeof(string) || change.PropertyType == typeof(DateTime) || change.PropertyType == typeof(DateTime?) || change.PropertyType == typeof(bool?) || change.PropertyType == typeof(bool)) arguments.Add("'" + change.GetValue(entity, null).ToString().Replace("'", "char(39)") + "'"); else arguments.Add(change.GetValue(entity, null)); } if (builder.Length == 0) throw new Exception("沒有任何屬性進行更新"); builder.Insert(0, " UPDATE " + string.Format("[{0}]", entityType.Name) + " SET "); builder.Append(" WHERE "); bool firstPrimaryKey = true; foreach (var primaryField in pkList) { if (firstPrimaryKey) firstPrimaryKey = false; else builder.Append(" AND "); object val = entityType.GetProperty(primaryField).GetValue(entity, null); Type pkType = entityType.GetProperty(primaryField).GetType(); builder.Append(GetEqualStatment(primaryField, arguments.Count, pkType)); arguments.Add(val); } return new Tuple<string, object[]>(builder.ToString(), arguments.ToArray()); } /// <summary> /// 構建Delete語句串 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="entity"></param> /// <returns></returns> private Tuple<string, object[]> CreateDeleteSql(TEntity entity) { if (entity == null) throw new ArgumentException("The database entity can not be null."); Type entityType = entity.GetType(); List<string> pkList = GetPrimaryKey().Select(i => i.Name).ToList(); if (pkList == null || pkList.Count == 0) throw new ArgumentException("The Table entity have not a primary key."); var arguments = new List<object>(); var builder = new StringBuilder(); builder.Append(" Delete from " + string.Format("[{0}]", entityType.Name)); builder.Append(" WHERE "); bool firstPrimaryKey = true; foreach (var primaryField in pkList) { if (firstPrimaryKey) firstPrimaryKey = false; else builder.Append(" AND "); Type pkType = entityType.GetProperty(primaryField).GetType(); object val = entityType.GetProperty(primaryField).GetValue(entity, null); builder.Append(GetEqualStatment(primaryField, arguments.Count, pkType)); arguments.Add(val); } return new Tuple<string, object[]>(builder.ToString(), arguments.ToArray()); } /// <summary> /// 構建Insert語句串 /// 主鍵為自增時，如果主鍵值為0，我們將主鍵插入到SQL串中 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="entity"></param> /// <returns></returns> private Tuple<string, object[]> CreateInsertSql(TEntity entity) { if (entity == null) throw new ArgumentException("The database entity can not be null."); Type entityType = entity.GetType(); var table = entityType.GetProperties().Where(i => i.PropertyType != typeof(EntityKey) && i.PropertyType != typeof(EntityState) && i.Name != "IsValid" && i.GetValue(entity, null) != null && !i.PropertyType.IsEnum && i.GetCustomAttributes(false).Where(j => j.GetType() == typeof(NavigationAttribute)) != null && (i.PropertyType.IsValueType || i.PropertyType == typeof(string))).ToArray();//過濾主鍵，航行屬性，狀態屬性等 var pkList = new List<string>(); if (GetPrimaryKey() != null)//有時主鍵可能沒有設計，這對於新增操作是可以的 pkList = GetPrimaryKey().Select(i => i.Name).ToList(); var arguments = new List<object>(); var fieldbuilder = new StringBuilder(); var valuebuilder = new StringBuilder(); fieldbuilder.Append(" INSERT INTO " + string.Format("[{0}]", entityType.Name) + " ("); foreach (var member in table) { if (pkList.Contains(member.Name) && Convert.ToString(member.GetValue(entity, null)) == "0") continue; object value = member.GetValue(entity, null); if (value != null) { if (arguments.Count != 0) { fieldbuilder.Append(", "); valuebuilder.Append(", "); } fieldbuilder.Append(member.Name); if (member.PropertyType == typeof(string) || member.PropertyType == typeof(DateTime) || member.PropertyType == typeof(DateTime?) || member.PropertyType == typeof(Boolean?) || member.PropertyType == typeof(Boolean) ) valuebuilder.Append("'{" + arguments.Count + "}'"); else valuebuilder.Append("{" + arguments.Count + "}"); if (value is string) value = value.ToString().Replace("'", "char(39)"); arguments.Add(value); } } fieldbuilder.Append(") Values ("); fieldbuilder.Append(valuebuilder.ToString()); fieldbuilder.Append(");"); return new Tuple<string, object[]>(fieldbuilder.ToString(), arguments.ToArray()); } /// <summary> /// /// <summary> /// 執行SQL，根據SQL操作的型別 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="list"></param> /// <param name="sqlType"></param> /// <returns></returns> /// </summary> /// <param name="list"></param> /// <param name="sqlType"></param> /// <returns></returns> private string DoSql(IEnumerable<TEntity> list, SqlType sqlType) { return DoSql(list, sqlType, null); } /// <summary> /// 執行SQL，根據SQL操作的型別 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="list"></param> /// <param name="sqlType"></param> /// <returns></returns> private string DoSql(IEnumerable<TEntity> list, SqlType sqlType, params string[] fieldParams) { var sqlstr = new StringBuilder(); switch (sqlType) { case SqlType.Insert: list.ToList().ForEach(i => { Tuple<string, object[]> sql = CreateInsertSql(i); sqlstr.AppendFormat(sql.Item1, sql.Item2); }); break; case SqlType.Update: list.ToList().ForEach(i => { Tuple<string, object[]> sql = CreateUpdateSql(i, fieldParams); sqlstr.AppendFormat(sql.Item1, sql.Item2); }); break; case SqlType.Delete: list.ToList().ForEach(i => { Tuple<string, object[]> sql = CreateDeleteSql(i); sqlstr.AppendFormat(sql.Item1, sql.Item2); }); break; default: throw new ArgumentException("請輸入正確的引數"); } return sqlstr.ToString(); } /// <summary> /// SQL操作型別 /// </summary> protected enum SqlType { Insert, Update, Delete, } #endregion }
以上六大部分就是我最新的EF架構的核心了，事實上，EF只是實現資料持久化的一種方式，在我的架構中還提到了XmlRepository,RedisRepository,Linq2SqlRepository等等，對於倉儲這塊感興趣的同學，可以與我一起去討論！我很希望有一天，我的底層
架構有這樣一個功能，那就是自動去選擇我的資料庫，如我的資料庫有db1,db2.....dbN，它們之間的資料是同步的（叢集），我能通過ＥＦ來實現我用哪臺資料伺服器，想想就很美，哈哈！