ado.net

　　数据库得操作无非是增删查改，增删改由ExecuteNonQuery实现，查由SqlDataReader实现，dataset主要用于绑定表格数据。

SqlDataReader

        public static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
        {
            SqlCommand sqlCommand = new SqlCommand();
            SqlDataReader result;
            try
            {
                connection.Open();
                PrepareCommand(sqlCommand, connection, transaction, commandType, commandText,
                    commandParameters);
                SqlDataReader sqlDataReader;
                if (connectionOwnership == SqlConnectionOwnership.External)
                {
                    sqlDataReader = sqlCommand.ExecuteReader();
                }
                else
                {
                    sqlDataReader = sqlCommand.ExecuteReader(CommandBehavior.CloseConnection);
                }
                bool flag2 = true;
                foreach (SqlParameter sqlParameter in sqlCommand.Parameters)
                {
                    if (sqlParameter.Direction != ParameterDirection.Input)
                    {
                        flag2 = false;
                    }
                }
                if (flag2)
                {
                    sqlCommand.Parameters.Clear();
                }
                result = sqlDataReader;
            }
            catch(Exception e)
            {
                throw e;
            }
            finally
            {

            }
            return result;
        }

 

SqlParameter

        public static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
        {
            if (command == null)
            {
                throw new ArgumentNullException("command");
            }
            if (commandParameters != null)
            {
                for (int i = 0; i < commandParameters.Length; i++)
                {
                    SqlParameter sqlParameter = commandParameters[i];
                    if (sqlParameter != null)
                    {
                        if ((sqlParameter.Direction == ParameterDirection.InputOutput ||
                            sqlParameter.Direction == ParameterDirection.Input) && sqlParameter.Value == null)
                        {
                            sqlParameter.Value = DBNull.Value;
                        }
                        command.Parameters.Add(sqlParameter);
                    }
                }
            }
        }


        public static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, 
            CommandType commandType, string commandText, SqlParameter[] commandParameters)
        {
            if (command == null)
            {
                throw new ArgumentNullException("command");
            }
            if (commandText == null || commandText.Length == 0)
            {
                throw new ArgumentNullException("commandText");
            }
            if (connection.State != ConnectionState.Open)
            {
                connection.Open();
            }
            command.Connection = connection;
            command.CommandText = commandText;
            if (transaction != null)
            {
                if (transaction.Connection == null)
                {
                    throw new ArgumentException("打开状态的事务允许数据操作回滚或者提交。", "事务");
                }
                command.Transaction = transaction;
            }
            command.CommandType = commandType;
            if (commandParameters != null)
            {
                AttachParameters(command, commandParameters);
            }
        }

 

DataSet

 public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, 
            string commandText, params SqlParameter[] commandParameters)
        {
            if (connection == null)
            {
                throw new ArgumentNullException("connection");
            }
            SqlCommand sqlCommand = new SqlCommand();
            
            PrepareCommand(sqlCommand, connection, null, commandType, commandText, commandParameters);
            DataSet result;
            using (SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(sqlCommand))
            {
                DataSet dataSet = new DataSet();
                sqlDataAdapter.Fill(dataSet);
                sqlCommand.Parameters.Clear();
              
                result = dataSet;
            }
            return result;
        }

 

源码

　　https://git.oschina.net/zkzk945/AdoNetSqlServer.git 源码实现了数据库得增删查改。