Manage data by using the DataAdapter and TableAdapter
DataAdapter
DbDataAdapter object is used to retrieve and update data between a data table and a data store.
If the connection is open, the DbDataAdapter
uses the open connection and leaves the connection open. If the connection is closed, DbDataAdapter
opens the connection, uses it, and then closes it automatically.
DbDataAdapter
has a SelectCommand
, InsertCommand
, UpdateCommand
, and DeleteCommand
properties.
Fill
method
Fill
methodThe Fill
method moves data from the data store to the DataTable
object you pass into this method. The Fill
method has several overloads, some of which accept only a data set as a parameter. When a data set is passed to the Fill
method, a new DataTable
object is created in the data set if a source DataTable
object is not specified.
Saving Changes
The Update
method saves the data table modifications to the database by retrieving the changes from the data table and then using the respective InsertCommand
, UpdateCommand
, or DeleteCommand
property to send the appropriate changes to the database on a row-by-row basis.
For the Update
method to work, all four commands must be assigned to the DbDataAdapter
object.
Normally, this means creating individual DbCommand
objects for each command. Another way to populate the DbDataAdapter
object’s commands is to use the DbCommandBuilder object.
DON’T EXECUTE TWICE! If you execute this code twice, an exception will be thrown indicating that you are trying to insert duplicate rows.
One way to increase update performance is to send the changes to the database server in batches by assigning a value to the DbDataAdapter
object’s UpdateBatchSize property. This property defaults to 1, which causes each change to be sent to the server on a row-by-row basis.
TableAdapter
A TableAdapter component fills a dataset with data from the database, based on one or more queries or stored procedures that you specify.
TableAdapters can also perform adds, updates, and deletes on the database to persist changes that you make to the dataset. You can also issue global commands that are unrelated to any specific table.
TableAdapters are generated by Visual Studio designers. If you are creating datasets programmatically, then use DataAdapter, which is a .NET class.
Methods
Member | Description |
| Populates the TableAdapter's associated data table with the results of the TableAdapter's |
| Sends changes back to the database and returns an integer that represents the number of rows affected by the update. |
| Returns a new DataTable that's filled with data. |
| Creates a new row in the data table. |
| Determines whether a data table is emptied before you call one of the |
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