單元測試實體框架中的動態查詢4

Question

當使用實體框架4.0實現工作單元模式時，使用對象上下文的CreateQuery方法創建動態查詢的能力是正確的設計是什麼？正確地說，我的意思是以某種方式設計我可以在模擬對象的單元測試中使用它。

謝謝。

Answer 1

不知道「正確」是什麼意思取決於你的情況，但一般的答案是你需要一些可以在測試過程中被替換的抽象。對於一些靈感，這裏是我們使用（我們用自我跟蹤POCO實體）

/// <summary> 
/// Object context interface for abstracting the service layer from the 
/// implementation details of object storage. 
/// </summary> 
public interface IObjectContext : IDisposable 
{ 
    /// <summary> 
    /// Returns the entity objects of the given type known by this object context. 
    /// </summary> 
    /// <typeparam name="TEntity">The type of the entity.</typeparam> 
    /// <returns>The instances of the given type already loaded into this object context</returns> 
    IEnumerable<TEntity> GetManagedEntities<TEntity>() where TEntity : EntityBase; 

    /// <summary> 
    /// Creates an object set for the provided entity type. 
    /// </summary> 
    /// <typeparam name="TEntity">The type of the entity.</typeparam> 
    /// <returns></returns> 
    IObjectSet<TEntity> CreateObjectSet<TEntity>() where TEntity : EntityBase; 

    /// <summary> 
    /// Applies the changes made to the provided entity object graph to this object context. 
    /// </summary> 
    /// <typeparam name="TEntity">The type of entity (inferred).</typeparam> 
    /// <param name="entity">The entity object graph that has been modified.</param> 
    void ApplyChanges<TEntity>(TEntity entity) where TEntity : EntityBase, IObjectWithChangeTracker; 

    /// <summary> 
    /// Saves the changes known by this object context instance to the database. 
    /// </summary> 
    void Save(); 

    /// <summary> 
    /// Creates a new logical unit of work spanning a single business transaction. 
    /// </summary> 
    IUnitOfWork CreateUnitOfWork(); 

    /// <summary> 
    /// Creates a new logical unit of work spanning a single business transaction. 
    /// </summary> 
    /// <param name="isolationLevel">The transaction isolation level used by the 
    /// unit of work ambient transaction.</param> 
    /// <returns></returns> 
    IUnitOfWork CreateUnitOfWork(IsolationLevel isolationLevel); 
} 

以及用於提取交易

/// <summary> 
/// Interface abstraction for a unit of work, aka all persistent work spanning a single 
/// business transaction and to be performed in unity. 
/// </summary> 
/// <remarks>Used to support outer and inner units of work where one outer UoW may consist 
/// of multiple nested inner UoW instances and have all of them share a transaction.</remarks> 
public interface IUnitOfWork : IDisposable 
{ 
    /// <summary> 
    /// Gets the transaction isolation level used by the unit of work ambient transaction. 
    /// </summary> 
    /// <value>The isolation level.</value> 
    IsolationLevel IsolationLevel { get; } 

    /// <summary> 
    /// Gets the transaction timeout time span used by the unit of work ambient transaction. 
    /// </summary> 
    /// <value>The transaction timeout duration.</value> 
    TimeSpan TransactionTimeout { get; } 

    /// <summary> 
    /// Completes the unit of work that this instance represents. 
    /// </summary> 
    /// <remarks> 
    /// For an outer unit of work, will persist all changes represented by this business 
    /// transaction and will then signal the ambient transaction in use as complete. 
    /// For an inner unit of work, will signal itself as completed to the outer unit of 
    /// work that it is part of. 
    /// </remarks> 
    void Complete(); 
} 

然後修改對象上下文生成的代碼來支持這些接口+實現你的UOW根據您的需求（爲簡潔起見，我們省略了實施）。 HTH