Updating data sources with dataadapters
When querying data, there are two mechanisms we can use: a Data Reader or a Data Adapter.
Even though we are comparing Data Reader & Data Adapter, underneath the abstractions, a Data Adapter uses a Data Reader to populate the returned Data Set or Data Table.
This tutorial describes only basic ways of working with data.
Besides, you can take advantage of using stored procedures, typed datasets and ORM solutions.
are used for controlling Datasets and it provides communication between Data Sets and Data Source.
Data Adapters make a connection with Data Source and then Fill Data to Data Sets. In this chapter, you learned how to work with Data Set and Data Table in C# ADO. You can locally work with the dataset and after completing all the modification, save back to the database.
The connected environment provides forward-only, read-only access to data in the data source and the ability to execute commands against the data source.
The connected classes provide a common way to work with connected data regardless of the underlying data source.
The goal of this tutorial is to retrieve and update the data from the table dept (the appropriate DDL/DML script is located at \Program Files\Devart\dot Connect\My SQL\Samples\- the default path of dot Connect for My SQL installation). NET Standard 1.3 compatible assemblies, because there are no base classes for them. Active = True ' modifying the third record my Data Table. Update() & " rows updated.") Dim my Row As Data Row Dim my Col As Data Column ' printing the Data Table content For Each my Row In my Data Table. Write Line() Next my Row Finally ' Active=false does not clear the data, but frees the resources allocated on the server, if any. Active = False End Try End Sub My Sql Data Set can be easily created with Devart Data Set Wizard and visually managed with Devart Data Set Manager.
My Sql Data Adapter and My Sql Data Table components are available for full . Thus, you cannot use disconnected model classes and My Sql Data Adapter in projects targeted . Rows(3)("DName") = "Researches" ' Update method executes the appropriate commands (delete, insert, or update) in the data source. Please refer to our Using Data Set Wizard and Using Data Set Manager articles.
NET, don't interoperate with datasource immediately. These classes provide the ability to work off-line against your data storage: Data Set, Data Table, Data Column, Data Row, Constraints, Data Relation, Data View, and Data Row View. Public Sub Use Data Table() Dim my Data Table As My Sql Data Table _ As New My Sql Data Table("SELECT * FROM Dept", "User Id=root; Host=localhost; Database=Test;") Try ' Fetch All=true means to retrieve data from server entirely when Data Table is opened.
We will use in our samples the classes from both models. ' By default, Fetch All is set to false - only minimal quantity of rows is requested at once, ' which leads to better initial response time and less network traffic. Fetch All = True ' populating Data Table with data from data source my Data Table. Write(my Row(my Col) & Vb Crlf) Next my Col Console.
Accessing Remote Database each time for updating or retrieving details are time-consuming so datasets help you to keep local database tables on your PC.Tags: Adult Dating, affair dating, sex dating