微软C# DBHelper类标准模型

using System; using System.Data; using System.Data.Common; using System.Configuration; public class DbHelper { private static string dbProviderName = ConfigurationManager.AppSettings["DbHelperProvider"]; private static string dbConnectionString = ConfigurationManager.AppSettings["DbHelperConnectionString"]; private DbConnection connection; public DbHelper() { this.connection = CreateConnection(DbHelper.dbConnectionString); } public DbHelper(string connectionString) { this.connection = CreateConnection(connectionString); } public static DbConnection CreateConnection() { DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName); DbConnection dbconn = dbfactory.CreateConnection(); dbconn.ConnectionString = DbHelper.dbConnectionString; return dbconn; } public static DbConnection CreateConnection(string connectionString) { DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName); DbConnection dbconn = dbfactory.CreateConnection(); dbconn.ConnectionString = connectionString; return dbconn; } public DbCommand GetStoredProcCommond(string storedProcedure) { DbCommand dbCommand = connection.CreateCommand(); dbCommand.CommandText = storedProcedure; dbCommand.CommandType = CommandType.StoredProcedure; return dbCommand; } public DbCommand GetSqlStringCommond(string sqlQuery) { DbCommand dbCommand = connection.CreateCommand(); dbCommand.CommandText = sqlQuery; dbCommand.CommandType = CommandType.Text; return dbCommand; } #region 增加参数 public void AddParameterCollection(DbCommand cmd, DbParameterCollection dbParameterCollection) { foreach (DbParameter dbParameter in dbParameterCollection) { cmd.Parameters.Add(dbParameter); } } public void AddOutParameter(DbCommand cmd, string parameterName, DbType dbType, int size) { DbParameter dbParameter = cmd.CreateParameter(); dbParameter.DbType = dbType; dbParameter.ParameterName = parameterName; dbParameter.Size = size; dbParameter.Direction = ParameterDirection.Output; cmd.Parameters.Add(dbParameter); } public void AddInParameter(DbCommand cmd, string parameterName, DbType dbType, object value) { DbParameter dbParameter = cmd.CreateParameter(); dbParameter.DbType = dbType; dbParameter.ParameterName = parameterName; dbParameter.Value = value; dbParameter.Direction = ParameterDirection.Input; cmd.Parameters.Add(dbParameter); } public void AddReturnParameter(DbCommand cmd, string parameterName, DbType dbType) { DbParameter dbParameter = cmd.CreateParameter(); dbParameter.DbType = dbType; dbParameter.ParameterName = parameterName; dbParameter.Direction = ParameterDirection.ReturnValue; cmd.Parameters.Add(dbParameter); } public DbParameter GetParameter(DbCommand cmd, string parameterName) { return cmd.Parameters[parameterName]; } #endregion 执行#region 执行 public DataSet ExecuteDataSet(DbCommand cmd) { DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName); DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter(); dbDataAdapter.SelectCommand = cmd; DataSet ds = new DataSet(); dbDataAdapter.Fill(ds); return ds; } public DataTable ExecuteDataTable(DbCommand cmd) { DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName); DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter(); dbDataAdapter.SelectCommand = cmd; DataTable dataTable = new DataTable(); dbDataAdapter.Fill(dataTable); return dataTable; } public DbDataReader ExecuteReader(DbCommand cmd) { cmd.Connection.Open(); DbDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection); return reader; } public int ExecuteNonQuery(DbCommand cmd) { cmd.Connection.Open(); int ret = cmd.ExecuteNonQuery(); cmd.Connection.Close(); return ret; } public object ExecuteScalar(DbCommand cmd) { cmd.Connection.Open(); object ret = cmd.ExecuteScalar(); cmd.Connection.Close(); return ret; } #endregion #region 执行事务 public DataSet ExecuteDataSet(DbCommand cmd,Trans t) { cmd.Connection = t.DbConnection; cmd.Transaction = t.DbTrans; DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName); DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter(); dbDataAdapter.SelectCommand = cmd; DataSet ds = new DataSet(); dbDataAdapter.Fill(ds); return ds; } public DataTable ExecuteDataTable(DbCommand cmd, Trans t) { cmd.Connection = t.DbConnection; cmd.Transaction = t.DbTrans; DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName); DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter(); dbDataAdapter.SelectCommand = cmd; DataTable dataTable = new DataTable(); dbDataAdapter.Fill(dataTable); return dataTable; } public DbDataReader ExecuteReader(DbCommand cmd, Trans t) { cmd.Connection.Close(); cmd.Connection = t.DbConnection; cmd.Transaction = t.DbTrans; DbDataReader reader = cmd.ExecuteReader(); DataTable dt = new DataTable(); return reader; } public int ExecuteNonQuery(DbCommand cmd, Trans t) { cmd.Connection.Close(); cmd.Connection = t.DbConnection; cmd.Transaction = t.DbTrans; int ret = cmd.ExecuteNonQuery(); return ret; } public object ExecuteScalar(DbCommand cmd, Trans t) { cmd.Connection.Close(); cmd.Connection = t.DbConnection; cmd.Transaction = t.DbTrans; object ret = cmd.ExecuteScalar(); return ret; } #endregion } public class Trans : IDisposable { private DbConnection conn; private DbTransaction dbTrans; public DbConnection DbConnection { get { return this.conn; } } public DbTransaction DbTrans { get { return this.dbTrans; } } public Trans() { conn = DbHelper.CreateConnection(); conn.Open(); dbTrans = conn.BeginTransaction(); } public Trans(string connectionString) { conn = DbHelper.CreateConnection(connectionString); conn.Open(); dbTrans = conn.BeginTransaction(); } public void Commit() { dbTrans.Commit(); this.Colse(); } public void RollBack() { dbTrans.Rollback(); this.Colse(); } public void Dispose() { this.Colse(); } public void Colse() { if (conn.State == System.Data.ConnectionState.Open) { conn.Close(); } } }
那么如何使用它呢?下面我给出一些基本的使用示例,基本能满足你大部分的数据库操作需要了.
1)直接执行sql语句

         DbHelper db = new DbHelper(); DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values(‘haha‘)"); db.ExecuteNonQuery(cmd);
2)执行存储过程

         DbHelper db = new DbHelper(); DbCommand cmd = db.GetStoredProcCommond("t1_insert"); db.AddInParameter(cmd, "@id", DbType.String, "heihei"); db.ExecuteNonQuery(cmd);
3)返回DataSet

         DbHelper db = new DbHelper(); DbCommand cmd = db.GetSqlStringCommond("select * from t1"); DataSet ds = db.ExecuteDataSet(cmd);
4)返回DataTable

         DbHelper db = new DbHelper(); DbCommand cmd = db.GetSqlStringCommond("t1_findall"); DataTable dt = db.ExecuteDataTable(cmd);
5)输入参数/输出参数/返回值的使用(比较重要哦)

         DbHelper db = new DbHelper(); DbCommand cmd = db.GetStoredProcCommond("t2_insert"); db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks); db.AddOutParameter(cmd, "@outString", DbType.String, 20); db.AddReturnParameter(cmd, "@returnValue", DbType.Int32); db.ExecuteNonQuery(cmd); string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value

6)DataReader使用

       DbHelper db = new DbHelper(); DbCommand cmd = db.GetStoredProcCommond("t2_insert"); db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks); db.AddOutParameter(cmd, "@outString", DbType.String, 20); db.AddReturnParameter(cmd, "@returnValue", DbType.Int32); using (DbDataReader reader = db.ExecuteReader(cmd)) { dt.Load(reader); } string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value


7)事务的使用.(项目中需要将基本的数据库操作组合成一个完整的业务流时,代码级的事务是必不可少的哦)

以上我们好像没有指定数据库连接字符串,大家如果看下DbHelper的代码,就知道要使用它必须在config中配置两个参数,如下:

     pubic void DoBusiness() { using (Trans t = new Trans()) { try { D1(t); throw new Exception();//如果有异常,会回滚滴 D2(t); t.Commit(); } catch { t.RollBack(); } } } public void D1(Trans t) { DbHelper db = new DbHelper(); DbCommand cmd = db.GetStoredProcCommond("t2_insert"); db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks); db.AddOutParameter(cmd, "@outString", DbType.String, 20); db.AddReturnParameter(cmd, "@returnValue", DbType.Int32); if (t == null) db.ExecuteNonQuery(cmd); else db.ExecuteNonQuery(cmd,t); string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value } public void D2(Trans t) { DbHelper db = new DbHelper(); DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values(‘..‘)"); if (t == null) db.ExecuteNonQuery(cmd); else db.ExecuteNonQuery(cmd, t); }
     <appSettings> <add key="DbHelperProvider" value="System.Data.SqlClient"/> <add key="DbHelperConnectionString" value="Data Source=(local);Initial Catalog=DbHelperTest;Persist Security Info=True;User ID=sa;Password=sa"/> appSettings>