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This article mainly explains "ADO. NET processing skills is what", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let Xiaobian take you to learn "ADO. NET processing skills is what" it!

The use of command constructors should be limited to design-time or ad-hoc situations. The required process of generating data adapter command attributes impedes performance. If you know the contents of INSERT/UPDATE/Delete statements beforehand, you should explicitly set them. A good design technique is to build stored procedures for INSERT/UPDATE/Delete commands and explicitly configure the data adapter command properties to use them.

The command constructor uses the SelectCommand attribute of the data adapter to determine the values of other command attributes. If the ADO. NET processing data adapter SelectCommand itself changes, be sure to call RefreshSchema to update the command properties.

If the command attribute is empty (command attributes are empty by default), the command constructor generates a command only for the data adapter command attribute. If you explicitly set a command attribute, the command constructor does not override it. If you want the command constructor to generate a command for a command property that has already been set, set the command property to null.

Batch ADO. NET processing statements

Many databases support combining and batching multiple command executions in a single command execution. For example, SQL Server allows you to separate commands with semicolons. Combining multiple commands into one reduces the number of accesses to the server and improves application performance. For example, you can store all deletions in your local application and issue a batch command call to delete them at the data source.

Although it improves performance, it also increases the complexity of updating data in the application management dataset. ADO. NET processing To keep things simple, you might want to create a data adapter for each table in your dataset.

Populating a dataset with multiple tables

If you use batch ADO. NET processing statements to retrieve multiple tables and populate a data set, *** the names of the tables use the table names specified by the Fill method, and the names of the subsequent tables are the names specified by the Fill method plus a number, increasing from 1. For example, if you run the following code:

'Visual Basic

Dim da As SqlDataAdapter = New SqlDataAdapter("SELECT * FROM Customers;

SELECT * FROM Orders;", myConnection)

Dim ds As DataSet = New DataSet()

da.Fill(ds, "Customers")

C#

SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Customers;

SELECT * FROM Orders;", myConnection);

DataSet ds = new DataSet();

da.Fill(ds, "Customers");

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