- 接着上篇[开源]Entity Framework 6 Repository 一种实现方式
- 由于Dapper 本身就是轻量级Orm特性，这里参考Creating a Data Repository using Dapper dynamic queries in dapper 代码，来解决实体类与Expression<Func<T, bool>> predicate问题；
- 您可以通过Nuget：Install-Package MasterChief.DotNet.Core.Dapper；
- 您可以通过GitHub：MasterChief 查看具体源码以及单元测试；
- 欢迎Star，欢迎Issues；
插播一条求职
- 小弟拥有多年C#开发经验，从事过路灯，消防平台物联网平台开发，坐标上海；
-
如果贵司在招聘，烦请大佬考虑下，联系邮箱:MeetYan@outlook.com；
基于Dapper 的Repository实现
public abstract class DapperDbContextBase : IDbContext
{
#region Constructors
/// <summary>
/// 构造函数
/// </summary>
/// <param name="connectString">连接字符串</param>
protected DapperDbContextBase(string connectString)
{
ConnectString = connectString;
}
#endregion Constructors
#region Properties
/// <summary>
/// 获取 是否开启事务提交
/// </summary>
public IDbTransaction CurrentTransaction { get; private set; }
#endregion Properties
#region Fields
/// <summary>
/// 当前数据库连接
/// </summary>
public IDbConnection CurrentConnection =>
TransactionEnabled ? CurrentTransaction.Connection : CreateConnection();
/// <summary>
/// 获取 是否开启事务提交
/// </summary>
public bool TransactionEnabled => CurrentTransaction != null;
/// <summary>
/// 连接字符串
/// </summary>
protected readonly string ConnectString;
#endregion Fields
#region Methods
/// <summary>
/// 显式开启数据上下文事务
/// </summary>
/// <param name="isolationLevel">指定连接的事务锁定行为</param>
public void BeginTransaction(IsolationLevel isolationLevel = IsolationLevel.Unspecified)
{
if (!TransactionEnabled) CurrentTransaction = CreateConnection().BeginTransaction(isolationLevel);
}
/// <summary>
/// 提交当前上下文的事务更改
/// </summary>
/// <exception cref="DataAccessException">提交数据更新时发生异常：" + 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("提交数据更新时发生异常：" + msg, sqlEx);
}
throw;
}
}
/// <summary>
/// 创建记录
/// </summary>
/// <param name="entity">需要操作的实体类</param>
/// <returns>操作是否成功</returns>
public bool Create<T>(T entity)
where T : ModelBase
{
ValidateOperator.Begin().NotNull(entity, "需要新增的数据记录");
// 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 测试代码
//string sql = @"INSERT INTO [dbo].[EFSample]
// ([ID]
// ,[CreateTime]
// ,[ModifyTime]
// ,[Available]
// ,[UserName])
//VALUES
// (@ID
// ,@CreateTime
// ,@ModifyTime
// ,@Available
// ,@UserName)";
//return CurrentConnection.Execute(sql, entity) > 0;
#endregion 测试代码
}
/// <summary>
/// 创建数据库连接IDbConnection
/// </summary>
/// <returns></returns>
public abstract IDbConnection CreateConnection();
/// <summary>
/// 删除记录
/// </summary>
/// <returns>操作是否成功</returns>
/// <param name="entity">需要操作的实体类.</param>
public bool Delete<T>(T entity)
where T : ModelBase
{
ValidateOperator.Begin().NotNull(entity, "需要删除的数据记录");
return CurrentConnection.Delete(entity);
}
/// <summary>
/// 执行与释放或重置非托管资源关联的应用程序定义的任务。
/// </summary>
public void Dispose()
{
if (CurrentTransaction != null)
{
CurrentTransaction.Dispose();
CurrentTransaction = null;
}
CurrentConnection?.Dispose();
}
/// <summary>
/// 条件判断是否存在
/// </summary>
/// <returns>是否存在</returns>
/// <param name="predicate">判断条件委托</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>
/// 根据id获取记录
/// </summary>
/// <returns>记录</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>
/// 条件获取记录集合
/// </summary>
/// <returns>集合</returns>
/// <param name="predicate">筛选条件.</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>
/// 条件获取记录第一条或者默认
/// </summary>
/// <returns>记录</returns>
/// <param name="predicate">筛选条件.</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>
/// 条件查询
/// </summary>
/// <returns>IQueryable</returns>
/// <param name="predicate">筛选条件.</param>
public IQueryable<T> Query<T>(Expression<Func<T, bool>> predicate = null)
where T : ModelBase
{
throw new NotImplementedException();
}
/// <summary>
/// 显式回滚事务，仅在显式开启事务后有用
/// </summary>
public void Rollback()
{
if (TransactionEnabled) CurrentTransaction.Rollback();
}
/// <summary>
/// 执行Sql 脚本查询
/// </summary>
/// <param name="sql">Sql语句</param>
/// <param name="parameters">参数</param>
/// <returns>集合</returns>
public IEnumerable<T> SqlQuery<T>(string sql, IDbDataParameter[] parameters)
{
ValidateOperator.Begin()
.NotNullOrEmpty(sql, "Sql语句");
var dataParameters = CreateParameter(parameters);
return CurrentConnection.Query<T>(sql, dataParameters, CurrentTransaction);
}
/// <summary>
/// 根据记录
/// </summary>
/// <returns>操作是否成功.</returns>
/// <param name="entity">实体类记录.</param>
public bool Update<T>(T entity)
where T : ModelBase
{
ValidateOperator.Begin().NotNull(entity, "需要更新的数据记录");
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>
/// 创建
/// </summary>
/// <param name="sample">EFSample</param>
/// <returns></returns>
public bool Create(EfSample sample)
{
using (IDbContext context = _contextFactory.Create())
{
return context.Create(sample);
}
}
/// <summary>
/// 条件查询
/// </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>
/// 根据主键查询
/// </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>
/// 条件查询集合
/// </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>
/// 添加判断是否存在
/// </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>
/// 脚本查询
/// </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>
/// 事务
/// </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();//开启事务
context.Create(sample);
context.Create(sample2);
context.Commit();
result = true;
}
catch (Exception)
{
context.Rollback();
result = false;
}
}
return result;
}
/// <summary>
/// 删除
/// </summary>
/// <param name="sample"></param>
/// <returns></returns>
public bool Delete(EfSample sample)
{
using (IDbContext context = _contextFactory.Create())
{
return context.Delete(sample);
}
}
}
结语
- Dapper与Entity Framework都是通过IRepository实现，所以您可以通过Ioc切换；
- 该篇的单元测试写法与上篇一致；
- 小弟不才，大佬轻拍；
