The Original value is the value that was used to populate the DataTable from the data source. If the tables from your data source have auto-incrementing columns, you can fill the columns in your DataSet either by returning the auto-increment value as an output parameter of a stored procedure and mapping that to a column in a table, by returning the auto-increment value in the first row of a result set returned by a stored procedure or SQL statement, or by using the RowUpdated event of the DataAdapter to execute an additional SELECT statement.
For more information and an example, see Retrieving Identity or Autonumber Values. In many circumstances, the order in which changes made through the DataSet are sent to the data source is important. For example, if a primary key value for an existing row is updated, and a new row has been added with the new primary key value as a foreign key, it is important to process the update before the insert.
You can then pass the returned DataRow array to the Update method of the DataAdapter to process the modified rows. By specifying a subset of rows to be updated, you can control the order in which inserts, updates, and deletes are processed. For example, the following code ensures that the deleted rows of the table are processed first, then the updated rows, and then the inserted rows.
The sample uses DataAdapter. AcceptChangesDuringFill to clone the data in the database. If the property is set as false, AcceptChanges is not called when filling the table, and the newly added rows are treated as inserted rows. So, the sample uses these rows to insert the new rows into the database. The samples uses DataAdapter. TableMappings to define the mapping between the source table and DataTable. When you create a DataTable, you can only write the data from database to the current version or the original version by setting the property as the LoadOption.
Upsert or the LoadOption. Delete ; In this example, I'll show you how to add edit, and remove, data from the Northwind database. I'll display the result of the Customers table in a DataGrid after adding, updating, and deleting data from the table. Listing show the code on the InsertCommand button-click event. NewRow method. AddWithKey; adapter. Tables [ "customers" ].
Add row ; adapter. Update ds, "Customers" ; dataGrid1. Show exp. Net, based on the Database Provider, there are distinct connection classes. The Command Object is also database specific. These command objects know what needs to be executed in the database. This object knows in which box the database is running, name of the DB to connect and the needed user name plus password to enter the database.
The Open method of this SqlConnection object opens the DB connection, granting further interaction possible. In our example we will use this SqlConnection object to open connection to the pubs DB by making use of connection string.
It takes the command in the CommandText property and Ado. Net will use this property when the it calls one of its execute method. The below list shows the three useful methods of SqlCommand object:.
The ExecuteScalar method gets a single value from the database. For example, using this method we can fetch Sum of Sales made by a product, Total number of records in the staff table, ID Keys by supplying filter conditions, etc. As this method works faster, we no need to go for Reader methods just to pull a single scalar value. ExecuteNonQuery is to do data change on the database. We will use ExecuteReader method when we need to bring rows and columns of data using the SQL select statements.
We should iterate through this object to get the needed values. In the above diagram, we can see that SqlCommand needs a DB connection to know where the DB lives to run the command on it.
The ExecuteReader method returns SqlDataReader, which needs to be looped to read the results from it. The middle of the form is having a multi-line text box which we will use to show all the Book Titles along with the price and other details. YogiHosting » ASP. Search for:. Introduction to ASP. Update Records using ADO. This tutorial is a part of ADO. NET series. Learn ADO.
NET Core Application 2. Create Records using ADO. NET Core Application 3. Read Records using ADO.
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