知识大全 ado.net快速上手实践篇（一）

Posted 2022-07-21 操作

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这两天重温经典对的东西稍微深入的了解了一下顺便写点代码练练手全当是复习笔记吧 一简单说说的大常用对象 既然说当然不能免俗地要提到大常用对象本文不会对的大对象和它们的关系进行过多阐释不过我们应该对下面这张图的结构有个了解

关于上图图示中的大对象经常做以数据为驱动的mis系统的童鞋应该不会陌生本文一笔带过下面我们一步一步实现以为核心的数据访问程序 二数据访问持久化层 IDbOperation接口代码 using System Collections Generic; using System Data; using System Data Common; namespace AdoNetDataaccess Core Contract public interface IDbOperation DbCommand CreateDbCommd(DbConnection sqlConn DbTransaction transaction string sqlStr CommandType cmdType List<DbParameter> listParams); DbParameter CreateDbPRameter(string paramName object paramValue); DbDataReader ExecuteReader(string sqlStr CommandType cmdType List<DbParameter> listParams); DataTable FillDataTable(string sqlStr CommandType cmdType List<DbParameter> listParams); DataSet FillDataSet(string sqlStr CommandType cmdType List<DbParameter> listParams); object ExecuteScalar(string sqlStr CommandType cmdType List<DbParameter> listParams); int ExecuteNonQuery(string sqlStr CommandType cmdType List<DbParameter> listParams); /// <summary> /// 批量插入 /// </summary> /// <param name= tableName >表名称</param> /// <param name= dt >组装好的要批量导入的datatable</param> /// <returns></returns> bool ExecuteBatchInsert(string tableName int batchSize int copyTimeout DataTable dt); void OpenConnection(); void CloseConnection(); 上面的接口包括增删改查批量插入以及数据库连接对象的连接和关闭等常用操作您可以根据命名和参数轻松理解函数的含义根据楼猪的开发经验对于平时的数据库操作上述方法差不多够用了当然您也可以按照自己需要重写组织添加其他函数 针对一种数据源的数据操作实现 底层的数据操作接口定义好后就要针对一种数据源具体实现上述的数据操作这里楼猪选择了Sql Server 我们也可以实现其他数据源的数据访问操作按照配置利用抽象工厂动态反射选择是哪一种数据源的实现这里按下不表有心的童鞋自己可以动手一试下面是具体的实现代码 using System; using System Collections Generic; using System Data; using System Data Common; using System Data SqlClient; using System Transactions; namespace AdoNetDataAccess Core Implement using AdoNetDataAccess Core Contract; public class SqlServer : IDbOperation IDisposable private int cmdTimeOut = ; private DbConnection sqlConn = null; private DbCommand cmd = null; private SqlServer() public SqlServer(string sqlConStr) sqlConn = new SqlConnection(sqlConStr); cmdTimeOut = sqlConn ConnectionTimeout; public SqlServer(string sqlConStr int timeOut) sqlConn = new SqlConnection(sqlConStr); if (timeOut < ) timeOut = sqlConn ConnectionTimeout; cmdTimeOut = timeOut; #region contract method public DbCommand CreateDbCommd(DbConnection sqlConn DbTransaction transaction string sqlStr CommandType cmdType List<DbParameter> listParams) DbCommand cmd = new SqlCommand(); cmd Connection = sqlConn; cmd CommandText = sqlStr; cmd CommandType = cmdType; if (transaction != null) cmd Transaction = transaction; if (listParams != null && listParams Count > ) cmd Parameters AddRange(listParams ToArray()); cmd CommandTimeout = cmdTimeOut; OpenConnection(); return cmd; public DbParameter CreateDbPrameter(string paramName object paramValue) SqlParameter sp = new SqlParameter(paramName paramValue); return sp; public DbDataReader ExecuteReader(string sqlStr CommandType cmdType List<DbParameter> listParams) DbDataReader rdr = null; try OpenConnection(); cmd = CreateDbCommd(sqlConn null sqlStr cmdType listParams); rdr = cmd ExecuteReader(); catch (Exception ex) throw ex; return rdr; public DataTable FillDataTable(string sqlStr CommandType cmdType List<DbParameter> listParams) OpenConnection(); DbTransaction trans = sqlConn BeginTransaction(); DbCommand cmd = CreateDbCommd(sqlConn trans sqlStr cmdType listParams); SqlDataAdapter sqlDataAdpter = new SqlDataAdapter(cmd as SqlCommand); DataTable dt = new DataTable(); try sqlDataAdpter Fill(dt); trans Commit(); catch (Exception e) trans Rollback(); throw new Exception( 执行数据库操作失败 sql: + sqlStr e); finally sqlDataAdpter Dispose(); cmd Dispose(); trans Dispose(); CloseConnection(); return dt; public DataSet FillDataSet(string sqlStr CommandType cmdType List<DbParameter> listParams) OpenConnection(); DbTransaction trans = sqlConn BeginTransaction(); DbCommand cmd = CreateDbCommd(sqlConn trans sqlStr cmdType listParams); SqlDataAdapter sqlDataAdpter = new SqlDataAdapter(cmd as SqlCommand); DataSet ds = new DataSet(); try sqlDataAdpter Fill(ds); trans Commit(); catch (Exception e) trans Rollback(); throw new Exception( 执行数据库操作失败 sql: + sqlStr e); finally sqlDataAdpter Dispose(); cmd Dispose(); trans Dispose(); CloseConnection(); return ds; public object ExecuteScalar(string sqlStr CommandType cmdType List<DbParameter> listParams) object result = null; OpenConnection(); DbTransaction trans = sqlConn BeginTransaction(); try cmd = CreateDbCommd(sqlConn trans sqlStr cmdType listParams); result = cmd ExecuteScalar(); trans Commit(); catch (Exception e) trans Rollback(); throw new Exception( 执行数据库操作失败 sql: + sqlStr e); finally trans Dispose(); CloseConnection(); return result; public int ExecuteNonQuery(string sqlStr CommandType cmdType List<DbParameter> listParams) int result = ; OpenConnection(); DbTransaction trans = sqlConn BeginTransaction(); try cmd = CreateDbCommd(sqlConn trans sqlStr cmdType listParams); result = cmd ExecuteNonQuery(); trans Commit(); catch (Exception e) trans Rollback(); throw new Exception( 执行数据库操作失败 sql: + sqlStr e); finally trans Dispose(); CloseConnection(); return result; /// <summary> /// 批量插入 /// </summary> /// <param name= tableName ></param> /// <param name= batchSize ></param> /// <param name= copyTimeout ></param> /// <param name= dt ></param> /// <returns></returns> public bool ExecuteBatchInsert(string tableName int batchSize int copyTimeout DataTable dt) bool flag = false; try using (TransactionScope scope = new TransactionScope()) OpenConnection(); using (SqlBulkCopy sbc = new SqlBulkCopy(sqlConn as SqlConnection)) //服务器上目标表的名称 sbc DestinationTableName = tableName; sbc BatchSize = batchSize; sbc BulkCopyTimeout = copyTimeout; for (int i = ; i < dt Columns Count; i++) //列映射定义数据源中的列和目标表中的列之间的关系 sbc ColumnMappings Add(dt Columns[i] ColumnName dt Columns[i] ColumnName); sbc WriteToServer(dt); flag = true; scope Complete();//有效的事务 catch (Exception ex) throw ex; return flag; public void OpenConnection() if (sqlConn State == ConnectionState Broken || sqlConn State == ConnectionState Closed) sqlConn Open(); public void CloseConnection() sqlConn Close(); #endregion #region dispose method /// <summary> /// dispose接口方法 /// </summary> public void Dispose() #endregion 到这里我们实现了SqlServer类里的方法对Ms SqlServer数据库我们就已经可以进行简单的基础的CRUD操作了 三简单直观的对象实体转换 在第二步中我们已经实现了简单的数据CRUD操作根据楼猪使用ORM的经验和习惯我们也应该对一些查询结果进行转换因为以类的组织方式比直接呈现对象更容易让人接受效率高低反在其次下面利用常见的反射原理简单实现一个对象实体转换器ModelConverter类代码 using System; using System Collections; using System Collections Generic; using System Data; using System Data Common; using System Reflection; using System Threading; namespace AdoNetDataAccess Core Obj Model using AdoNetDataAccess Core Contract; public sealed class ModelConverter private static readonly object objSync = new object(); #region query for list /// <summary> /// 查询数据表项并转换为对应实体 /// </summary> /// <typeparam name= T ></typeparam> /// <param name= objType ></param> /// <param name= rdr ></param> /// <returns></returns> public static IList<T> QueryForList<T>(string sqlStr CommandType cmdType List<DbParameter> listParams Type objType IDbOperation dbOperation) where T : class new() IDataReader rdr = dbOperation ExecuteReader(sqlStr cmdType listParams); IList<T> listModels = new List<T>(); try Monitor Enter(objSync); Hashtable ht = CreateHashColumnName(rdr); while (rdr Read()) Object obj = Activator CreateInstance(objType); PropertyInfo[] properties = objType GetProperties(); foreach (PropertyInfo propInfo in properties) string columnName = propInfo Name ToUpper(); if (ht ContainsKey(columnName) == false) continue; int index = rdr GetOrdinal(propInfo Name); object columnValue = rdr GetValue(index); if (columnValue != System DBNull Value) SetValue(propInfo obj columnValue); T model = default(T); model = obj as T; listModels Add(model); finally rdr Close(); rdr Dispose(); Monitor Exit(objSync); return listModels; #endregion #region query for dictionary /// <summary> /// 查询数据表项并转换为对应实体 /// </summary> /// <typeparam name= K ></typeparam> /// <typeparam name= T ></typeparam> /// <param name= key >字典对应key列名</param> /// <param name= objType ></param> /// <param name= rdr ></param> /// <returns></returns> public static IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr CommandType cmdType List<DbParameter> listParams Type objType IDbOperation dbOperation) where T : class new() IDataReader rdr = dbOperation ExecuteReader(sqlStr cmdType listParams); IDictionary<K T> dictModels = new Dictionary<K T>(); try Monitor Enter(objSync); Hashtable ht = CreateHashColumnName(rdr); while (rdr Read()) Object obj = Activator CreateInstance(objType); PropertyInfo[] properties = objType GetProperties(); object dictKey = null; foreach (PropertyInfo propInfo in properties) string columnName = propInfo Name ToUpper(); if (ht ContainsKey(columnName) == false) continue; int index = rdr GetOrdinal(propInfo Name); object columnValue = rdr GetValue(index); if (columnValue != System DBNull Value) SetValue(propInfo obj columnValue); if (string Compare(columnName key ToUpper()) == ) dictKey = columnValue; T model = default(T); model = obj as T; K objKey = (K)dictKey; dictModels Add(objKey model); finally rdr Close(); rdr Dispose(); Monitor Exit(objSync); return dictModels; #endregion #region internal util private static Hashtable CreateHashColumnName(IDataReader rdr) int len = rdr FieldCount; Hashtable ht = new Hashtable(len); for (int i = ; i < len; i++) string columnName = rdr GetName(i) ToUpper(); //不区分大小写 string columnRealName = rdr GetName(i); if (ht ContainsKey(columnName) == false) ht Add(columnName columnRealName); return ht; private static void SetValue(PropertyInfo propInfo Object obj object objValue) try propInfo SetValue(obj objValue null); catch object realValue = null; try realValue = Convert ChangeType(objValue propInfo PropertyType); propInfo SetValue(obj realValue null); catch (Exception ex) string err = ex Message; //throw ex; //在数据库数据有不符合规范的情况下应该及时抛出异常 #endregion 到这里简单的数据访问持久化层就实现了下面模仿楼猪使用的写个伪SqlMapper 改善一下调用形式丰富一下调用方法让方法辨识度更高 四实现伪SqlMapper BaseMapper类 代码 using System; using System Collections Generic; using System Data; using System Data Common; using System Data SqlClient; namespace AdoNetDataAccess Mapper using AdoNetDataAccess Core Contract; public abstract class BaseMapper public IDbOperation CurrentDbOperation; #region query for list public abstract IList<T> QueryForList<T>(string sqlStr) where T : class new(); public abstract IList<T> QueryForList<T>(string sqlStr Type objType) where T : class new(); public abstract IList<T> QueryForList<T>(string sqlStr CommandType cmdType List<DbParameter> listParams) where T : class new(); public abstract IList<T> QueryForList<T>(string sqlStr CommandType cmdType List<DbParameter> listParams Type objType) where T : class new(); #endregion #region query for dictionary public abstract IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr) where T : class new(); public abstract IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr Type objType) where T : class new(); public abstract IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr CommandType cmdType Type objType) where T : class new(); public abstract IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr CommandType cmdType List<DbParameter> listParams Type objType) where T : class new(); #endregion #region dataset datatable public abstract DataTable FillDataTable(string sqlStr CommandType cmdType List<DbParameter> listParams); public abstract DataSet FillDataSet(string sqlStr CommandType cmdType List<DbParameter> listParams); #endregion #region ExecuteScalar public abstract object ExecuteScalar(string sqlStr CommandType cmdType List<DbParameter> listParams); #endregion #region insert public abstract int Insert(string sqlStr); public abstract int Insert(string sqlStr CommandType cmdType List<DbParameter> listParams); public abstract bool BatchInsert(string tableName int batchSize int copyTimeout DataTable dt); #endregion #region delete public abstract int Delete(string sqlStr); public abstract int Delete(string sqlStr CommandType cmdType List<DbParameter> listParams); #endregion #region update public abstract int Update(string sqlStr); public abstract int Update(string sqlStr CommandType cmdType List<DbParameter> listParams); #endregion 上面代码中的方法您是不是很熟悉呢？呵呵使用的童鞋应该会和楼猪产生更多的共鸣 SqlMapper类 代码 using System; using System Collections Generic; using System Data; using System Data Common; namespace AdoNetDataAccess Mapper using AdoNetDataAccess Core Contract; using AdoNetDataAccess Core Obj Model; public class SqlMapper : BaseMapper private SqlMapper() public SqlMapper(IDbOperation dbOperation) this CurrentDbOperation = dbOperation; #region query for list public override IList<T> QueryForList<T>(string sqlStr) return QueryForList<T>(sqlStr CommandType Text null typeof(T)); public override IList<T> QueryForList<T>(string sqlStr Type objType) return QueryForList<T>(sqlStr CommandType Text null objType); public override IList<T> QueryForList<T>(string sqlStr CommandType cmdType List<DbParameter> listParams) return QueryForList<T>(sqlStr cmdType listParams typeof(T)); public override IList<T> QueryForList<T>(string sqlStr CommandType cmdType List<DbParameter> listParams Type objType) return ModelConverter QueryForList<T>(sqlStr cmdType listParams objType this CurrentDbOperation); #endregion #region query for dictionary public override IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr) return QueryForDictionary<K T>(key sqlStr CommandType Text null typeof(T)); public override IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr Type objType) return QueryForDictionary<K T>(key sqlStr CommandType Text null objType); public override IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr CommandType cmdType Type objType) return QueryForDictionary<K T>(key sqlStr cmdType null objType); public override IDictionary<K T> QueryForDictionary<K T>(string key string sqlStr CommandType cmdType List<DbParameter> listParams Type objType) return ModelConverter QueryForDictionary<K T>(key sqlStr cmdType listParams objType this CurrentDbOperation); #endregion #region dataset datatable public override DataTable FillDataTable(string sqlStr CommandType cmdType List<DbParameter> listParams) return this CurrentDbOperation FillDataTable(sqlStr cmdType listParams); public override DataSet FillDataSet(string sqlStr CommandType cmdType List<DbParameter> listParams) return this CurrentDbOperation FillDataSet(sqlStr cmdType listParams); #endregion #region ExecuteScalar public override object ExecuteScalar(string sqlStr CommandType cmdType List<DbParameter> listParams) return this CurrentDbOperation ExecuteScalar(sqlStr cmdType listParams); #endregion #region insert public override int Insert(string sqlStr) object obj = ExecuteScalar(sqlStr CommandType Text null); int id = obj == null ? : int Parse(obj ToString()); return id; public override int Insert(string sqlStr CommandType cmdType List<DbParameter> listParams) object obj = ExecuteScalar(sqlStr cmdType listParams); int id = obj == null ? : int Parse(obj ToString()); return id; /// <summary> /// 批量插入 /// </summary> /// <param name= tableName ></param> /// <param name= batchSize ></param> /// <param name= copyTimeout ></param> /// <param name= dt ></param> /// <returns></returns> public override bool BatchInsert(string tableName int batchSize int copyTimeout DataTable dt) return this CurrentDbOperation ExecuteBatchInsert(tableName batchSize copyTimeout dt); #endregion #region delete public override int Delete(string sqlStr) return CommitSql(sqlStr CommandType Text null); public override int Delete(string sqlStr CommandType cmdType List<DbParameter> listParams) return CommitSql(sqlStr cmdType listParams); #endregion #region update public override int Update(string sqlStr) return CommitSql(sqlStr CommandType Text null); public override int Update(string sqlStr CommandType cmdType List<DbParameter> listParams) return CommitSql(sqlStr cmdType listParams); #endregion #region mit and execute sql private int CommitSql(string sqlStr CommandType cmdType List<DbParameter> listParams) return this CurrentDbOperation ExecuteNonQuery(sqlStr cmdType listParams); #endregion #region dbparameter public DbParameter CreateParameter(string paraName object paramValue) return this CurrentDbOperation CreateDbPrameter(paraName paramValue); public List<DbParameter> CreateParameterList(string[] paraNames object[] paramValues) List<DbParameter> listParams = new List<DbParameter>(); try if (paraNames Length != paramValues Length) throw new Exception( Param name and value is not equal ); for (int i = ; i < paraNames Length; i++) DbParameter param = CreateParameter(paraNames[i] paramValues[i]); listParams Add(param); catch (Exception ex) throw ex; return listParams; #endregion 上面的方法丰富实现了CRUD的常见操作其实主要还是调用了IDbOperation接口和方法 cha138/Article/program/ASP/201311/21746