接著上篇[開源]Entity Framework 6 Repository 一種實現方式

由于Dapper 本身就是輕量級Orm特性，這里參考Creating a Data Repository using Dapper dynamic queries in dapper 代碼，來解決實體類與Expression<Func<T, bool>> predicate問題；

您可以通過Nuget：Install-Package MasterChief.DotNet.Core.Dapper；

您可以通過GitHub：MasterChief 查看具體源碼以及單元測試；

歡迎Star，歡迎Issues；

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插播一條求職

小弟擁有多年C#開發經驗，從事過路燈，消防平臺物聯網平臺開發，坐標上海；

如果貴司在招聘，煩請大佬考慮下，聯系郵箱:MeetYan@outlook.com；

基于Dapper 的Repository實現

public abstract class DapperDbContextBase : IDbContext {#region Constructors/// <summary>/// 構造函數/// </summary>/// <param name="connectString">連接字符串</param>protected DapperDbContextBase(string connectString){ConnectString = connectString;}#endregion Constructors#region Properties/// <summary>/// 獲取 是否開啟事務提交/// </summary>public IDbTransaction CurrentTransaction { get; private set; }#endregion Properties#region Fields/// <summary>/// 當前數據庫連接/// </summary>public IDbConnection CurrentConnection =>TransactionEnabled ? CurrentTransaction.Connection : CreateConnection();/// <summary>/// 獲取 是否開啟事務提交/// </summary>public bool TransactionEnabled => CurrentTransaction != null;/// <summary>/// 連接字符串/// </summary>protected readonly string ConnectString;#endregion Fields#region Methods/// <summary>/// 顯式開啟數據上下文事務/// </summary>/// <param name="isolationLevel">指定連接的事務鎖定行為</param>public void BeginTransaction(IsolationLevel isolationLevel = IsolationLevel.Unspecified){if (!TransactionEnabled) CurrentTransaction = CreateConnection().BeginTransaction(isolationLevel);}/// <summary>/// 提交當前上下文的事務更改/// </summary>/// <exception cref="DataAccessException">提交數據更新時發生異常：" + msg</exception>public void Commit(){if (TransactionEnabled)try{CurrentTransaction.Commit();}catch (Exception ex){if (ex.InnerException?.InnerException is SqlException sqlEx){var msg = DataBaseHelper.GetSqlExceptionMessage(sqlEx.Number);throw new DataAccessException("提交數據更新時發生異常：" + msg, sqlEx);}throw;}}/// <summary>/// 創建記錄/// </summary>/// <param name="entity">需要操作的實體類</param>/// <returns>操作是否成功</returns>public bool Create<T>(T entity)where T : ModelBase{ValidateOperator.Begin().NotNull(entity, "需要新增的數據記錄");// insert single data always return 0 but the data is inserted in database successfully//https://github.com/StackExchange/Dapper/issues/587//List<T> data = new List<T>() { entity };return CurrentConnection.Insert(new List<T> {entity}, CurrentTransaction) > 0;#region 測試代碼//string sql = @"INSERT INTO [dbo].[EFSample]// ([ID]// ,[CreateTime]// ,[ModifyTime]// ,[Available]// ,[UserName])//VALUES// (@ID// ,@CreateTime// ,@ModifyTime// ,@Available// ,@UserName)";//return CurrentConnection.Execute(sql, entity) > 0;#endregion 測試代碼}/// <summary>/// 創建數據庫連接IDbConnection/// </summary>/// <returns></returns>public abstract IDbConnection CreateConnection();/// <summary>/// 刪除記錄/// </summary>/// <returns>操作是否成功</returns>/// <param name="entity">需要操作的實體類.</param>public bool Delete<T>(T entity)where T : ModelBase{ValidateOperator.Begin().NotNull(entity, "需要刪除的數據記錄");return CurrentConnection.Delete(entity);}/// <summary>/// 執行與釋放或重置非托管資源關聯的應用程序定義的任務。/// </summary>public void Dispose(){if (CurrentTransaction != null){CurrentTransaction.Dispose();CurrentTransaction = null;}CurrentConnection?.Dispose();}/// <summary>/// 條件判斷是否存在/// </summary>/// <returns>是否存在</returns>/// <param name="predicate">判斷條件委托</param>public bool Exist<T>(Expression<Func<T, bool>> predicate = null)where T : ModelBase{var tableName = GetTableName<T>();var queryResult = DynamicQuery.GetDynamicQuery(tableName, predicate);var result =CurrentConnection.ExecuteScalar(queryResult.Sql, (object) queryResult.Param, CurrentTransaction);return result != null;}/// <summary>/// 根據id獲取記錄/// </summary>/// <returns>記錄</returns>/// <param name="id">id.</param>public T GetByKeyId<T>(object id)where T : ModelBase{ValidateOperator.Begin().NotNull(id, "Id");return CurrentConnection.Get<T>(id, CurrentTransaction);}/// <summary>/// 條件獲取記錄集合/// </summary>/// <returns>集合</returns>/// <param name="predicate">篩選條件.</param>public List<T> GetList<T>(Expression<Func<T, bool>> predicate = null)where T : ModelBase{var tableName = GetTableName<T>();var queryResult = DynamicQuery.GetDynamicQuery(tableName, predicate);return CurrentConnection.Query<T>(queryResult.Sql, (object) queryResult.Param, CurrentTransaction).ToList();}/// <summary>/// 條件獲取記錄第一條或者默認/// </summary>/// <returns>記錄</returns>/// <param name="predicate">篩選條件.</param>public T GetFirstOrDefault<T>(Expression<Func<T, bool>> predicate = null)where T : ModelBase{var tableName = GetTableName<T>();var queryResult = DynamicQuery.GetDynamicQuery(tableName, predicate);return CurrentConnection.QueryFirst<T>(queryResult.Sql, (object) queryResult.Param, CurrentTransaction);}/// <summary>/// 條件查詢/// </summary>/// <returns>IQueryable</returns>/// <param name="predicate">篩選條件.</param>public IQueryable<T> Query<T>(Expression<Func<T, bool>> predicate = null)where T : ModelBase{throw new NotImplementedException();}/// <summary>/// 顯式回滾事務，僅在顯式開啟事務后有用/// </summary>public void Rollback(){if (TransactionEnabled) CurrentTransaction.Rollback();}/// <summary>/// 執行Sql 腳本查詢/// </summary>/// <param name="sql">Sql語句</param>/// <param name="parameters">參數</param>/// <returns>集合</returns>public IEnumerable<T> SqlQuery<T>(string sql, IDbDataParameter[] parameters){ValidateOperator.Begin().NotNullOrEmpty(sql, "Sql語句");var dataParameters = CreateParameter(parameters);return CurrentConnection.Query<T>(sql, dataParameters, CurrentTransaction);}/// <summary>/// 根據記錄/// </summary>/// <returns>操作是否成功.</returns>/// <param name="entity">實體類記錄.</param>public bool Update<T>(T entity)where T : ModelBase{ValidateOperator.Begin().NotNull(entity, "需要更新的數據記錄");return CurrentConnection.Update(entity, CurrentTransaction);}private DapperParameter CreateParameter(IDbDataParameter[] parameters){if (!(parameters?.Any() ?? false)) return null;var dataParameters = new DapperParameter();foreach (var parameter in parameters) dataParameters.Add(parameter);return dataParameters;}private string GetTableName<T>()where T : ModelBase{var tableCfgInfo = AttributeHelper.Get<T, TableAttribute>();return tableCfgInfo != null ? tableCfgInfo.Name.Trim() : typeof(T).Name;}#endregion Methods }

使用方法

public class SampleService : ISampleService {private readonly IDatabaseContextFactory _contextFactory;public SampleService(IDatabaseContextFactory contextFactory){_contextFactory = contextFactory;}/// <summary>/// 創建/// </summary>/// <param name="sample">EFSample</param>/// <returns></returns>public bool Create(EfSample sample){using (IDbContext context = _contextFactory.Create()){return context.Create(sample);}}/// <summary>/// 條件查詢/// </summary>/// <param name="predicate">The predicate.</param>/// <returns></returns>/// <exception cref="NotImplementedException"></exception>public EfSample GetFirstOrDefault(Expression<Func<EfSample, bool>> predicate = null){using (IDbContext context = _contextFactory.Create()){return context.GetFirstOrDefault(predicate);}}/// <summary>/// 根據主鍵查詢/// </summary>/// <param name="id">The identifier.</param>/// <returns></returns>/// <exception cref="NotImplementedException"></exception>public EfSample GetByKeyId(Guid id){using (IDbContext context = _contextFactory.Create()){return context.GetByKeyId<EfSample>(id);}}/// <summary>/// 條件查詢集合/// </summary>/// <param name="predicate">The predicate.</param>/// <returns></returns>public List<EfSample> GetList(Expression<Func<EfSample, bool>> predicate = null){using (IDbContext context = _contextFactory.Create()){return context.GetList(predicate);}}/// <summary>/// 添加判斷是否存在/// </summary>/// <param name="predicate">The predicate.</param>/// <returns></returns>public bool Exist(Expression<Func<EfSample, bool>> predicate = null){using (IDbContext context = _contextFactory.Create()){return context.Exist(predicate);}}/// <summary>/// 腳本查詢/// </summary>/// <param name="sql">The SQL.</param>/// <param name="parameter">DbParameter[]</param>/// <returns></returns>public List<EfSample> SqlQuery(string sql, DbParameter[] parameter){using (IDbContext context = _contextFactory.Create()){return context.SqlQuery<EfSample>(sql, parameter)?.ToList();}}/// <summary>/// 更新/// </summary>/// <param name="sample">The sample.</param>/// <returns></returns>public bool Update(EfSample sample){using (IDbContext context = _contextFactory.Create()){return context.Update(sample);}}/// <summary>/// 事務/// </summary>/// <param name="sample">The sample.</param>/// <param name="sample2">The sample2.</param>/// <returns></returns>public bool CreateWithTransaction(EfSample sample, EfSample sample2){bool result;using (IDbContext context = _contextFactory.Create()){try{context.BeginTransaction();//開啟事務context.Create(sample);context.Create(sample2);context.Commit();result = true;}catch (Exception){context.Rollback();result = false;}}return result;}/// <summary>/// 刪除/// </summary>/// <param name="sample"></param>/// <returns></returns>public bool Delete(EfSample sample){using (IDbContext context = _contextFactory.Create()){return context.Delete(sample);}} }

結語

Dapper與Entity Framework都是通過IRepository實現，所以您可以通過Ioc切換；

該篇的單元測試寫法與上篇一致；

小弟不才，大佬輕拍；

轉載于:https://www.cnblogs.com/MeetYan/p/10681353.html

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