Databases
StackOverflow2013
Postsdbo
POWorking with database confusion in C#
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWorking with database confusion in C#
    primarykey
    data
    text
    <p>I am trying to learn about how to work with databases in C# and I have gotten to a part in a tutorial when I have to work with DataSet , SqlDataAdapter and SqlCommandBuilder.This is the code I wrote in the example in the tutorial:</p> <pre><code> public void InitData() { //instantiate the connection conn = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=\"D:\\Projects IDE\\Visual Studio\\Exercitii\\Console.app\\WindowsFormsApplication1\\WindowsFormsApplication1\\PlanetWrox.mdf\";Integrated Security=True;User Instance=True"); //1.instantiate a new DataSet dsCustomers = new DataSet(); //2.init SqlDataAdapter with select command and connection daCustomers = new SqlDataAdapter("SELECT Id ,Name, SortOrder FROM Genre", conn); // 3. fill in insert, update, and delete commands SqlCommandBuilder cmdBldr = new SqlCommandBuilder(daCustomers); // 4. fill the dataset daCustomers.Fill(dsCustomers, tableName); } public void btnUpdateClicked(object sender, EventArgs e) { // write changes back to DataBase daCustomers.Update(dsCustomers, tableName); } </code></pre> <p>There are a couple of things I do not understand here:</p> <p>The first thing I noticed is that I do not have to open and close the database.From what limited knoledge I have about databases I know that in order to acces the data you have to open a connection to it and after you are done you have to close it.This must happen somewhere behind the scene.Is that righT? If that is so witch method does that?</p> <p>The second question is regarding the SqlDataAdapter and SqlCommandBuilder.I do not understand what does SqlCommandBuilder does here.Isen't the SqlDataAdapter the one that is executing the sql query? </p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USFurqan Safdar
    1. USNistor Alexandru
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWorking with database confusion in C#
      1. This table or related slice is empty.
      1. VTUpMod
    1. COWhen you call daCustomers.Fill(..) ADO.NET open and close connection to database for you
      singulars
      1. POWorking with database confusion in C#
      1. USDanilo Vulović
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload