C database operation summary

1, common T-Sql statement
        query: SELECT * FROM tb_test WHERE ID='1' AND name='xia'
                              SELECT * FROM tb_test
          insert: INSERT INTO tb_test VALUES('xia','123')
                                  INSERT INTO tb_test(name) VALUES('xia')
          update: UPDATE tb_test SET password='234' WHERE ID='1'
          delete: DELETE FROM tb_test WHERE ID='1'
                                DELETE tb_test WHERE ID='1'
Get the database connection string in vs2010
          string connectionString = Properties.Settings.Default.DatabaseTestConnectionString;
3, SqlCommand type
           
           

       using (SqlConnection connection = new SqlConnection(connectionString))
       {
             try
             {
                    SqlCommand command = new SqlCommand(selectStr, connection);
                    command.Connection.Open();
                    SqlDataReader reader = command.ExecuteReader();
                     while (reader.Read())
                             label1.Text = "name : " + reader["name"].ToString();    // Data is read 
                     command.Connection.Close();
               }
              catch (SqlException ex)
              {
                    throw ex;
              } 
       }
       

            insert, modify, delete:
           

       using (SqlConnection connection = new SqlConnection(connectionString))
       {
             try
             {
                    SqlCommand command = new SqlCommand(cmdStr, connection);
                    command.Connection.Open();
                    command.ExecuteNonQuery();
                    command.Connection.Close();
              }
              catch (SqlException ex)
              {
                    throw ex;
              }
      }

4, DataTable type, query, add, modify, delete
          DataTable class is used when querying, adding, deleting, and modifying         DataTable
          string selectStr = "SELECT * FROM tb_test2";
          enquiries:
         

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
             try
             {
                    SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                    DataTable dataTable = new DataTable();
                    adapter.Fill(dataTable);
                    // Data is read 
                    label1.Text = dataTable.Rows[0][0].ToString();
              }
             catch (SqlException ex)
             {
                     throw ex;
              }
      }
      

         
         

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
           try
           {
                 SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                 DataTable dataTable = new DataTable();
                 adapter.Fill(dataTable);
                  // Add data 
                 DataRow newRow = dataTable.NewRow();
                 newRow["id"] = "tesr";
                 newRow["name"] = "111";
                 dataTable.Rows.Add(newRow);
                 SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                 adapter.Update(dataTable); // Update to database 
            }
            catch (SqlException ex)
            {
                 throw ex;
            }
      }
      

         
         

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
            try
            {
                  SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                  DataTable dataTable = new DataTable();
                  adapter.Fill(dataTable);
                  // Modify the data 
                 DataRow updateRow = dataTable.Rows[0];
                 updateRow["id"] = "update";
                 updateRow["name"] = "222";
                 SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                 adapter.Update(dataTable); // Update to database 
            }
           catch (SqlException ex)
           {
                 throw ex;
           }
      }
      

          delete:
         

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
            try
            {
                   SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                   DataTable dataTable = new DataTable();
                   adapter.Fill(dataTable);
                   dataTable.Rows[0].Delete(); // Delete records 
                   SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                   adapter.Update(dataTable); // Update to database 
             }
            catch (SqlException ex)
            {
                   throw ex;
            } 
      }

5, DataSet type
          DataSet operation is basically the same as DataTabel operation, except that DataSet can store more than one table, so I will introduce more
6. Personal summary