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[.net] Edit data

Started by H0bbes Jan 17, 2005 at 5:28 AM 1 reply 700+ views

Original Post

Jan 17, 2005 at 5:28 AM

Anyone know something that can provide easier access to the data of data base. i want to do something like that when i move to the next row of data that is editing i want to show all data in the correct textbox. however i don't want to do txBox1.text= ..... for all textbox, i want a component that get the data directly from the data base. Anyone know one or some good sugestion to do that? I'm using vb.net

ernow

Jan 17, 2005 at 6:23 AM

What you want is databinding. -Directly- to the database does not exist in .NET. Microsoft chose to use the disconnected way of editing data.

Briefly: Get the data into a DataSet using a DataAdapter, a Command and a Connection object. Bind textboxes and other controls to columns of datatables in the dataset (DataSource/DataMember/DataField properties). Use a CurrencyManager to navigate through the Dataset. Call Update on the DataAdapter to synchronize with the Database.

Mind you: this is not 'easy'. Many aspects like concurrency and locking should be considered. Take a look at samples in the MSDN to learn this stuff.

Cheers

DaWanderer

Jan 17, 2005 at 3:26 PM

Visual Studio 2005 will have direct support for this kind of data binding. In the examples I've seen, you can simply drag the columns from the Server Explorer and it will handle the back and forth stuff.
Until then, I've used a simple method to avoid having to type textBox1.Text = ... for every field. In my Form_Load method, I set up a hashtable with each field name from the data base bound to a control like this:

FieldControlHash["FirstName"] = textBox1;FieldControlHash["BirthDate"] = dateTimePicker1;//...etc.

To copy data into the controls, I run through all the columns in the DataTable returned from my query, match them with the FieldControlHash, and then call a function like this for each control:

void SetValue(object InputControl, object Value){   if (InputControl is TextBox)   {      ((TextBox)InputControl).Text = Value.ToString();   }   else if (InputControl is DateTimePicker)   {      ((DateTimePicker)InputControl).Value = (DateTime)Value;   }}

To copy date back from the controls, I create a GetValue function that does the exact opposite. From there, you use Update like ernow suggested or write your own function that generates the SQL.
This way is harder than DataBinding like ernow suggested, but I use it because a lot of the GUI controls I use do not support data binding. With this method, I can just add another line to my Get/Set Value functions and have support for a new control.

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