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This article focuses on "how to use ADO.NET SqlCommand objects". Friends who are interested might as well take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor show you how to use ADO.NET SqlCommand objects.

As those of you who know ADO.NET know, ADO.NET provides us with a variety of object models, and here are two typical object models, both under the System.Data.SqlClient namespace. Next, let's take a quick look at it. In the past, when writing programs, we can design calls to execute Command object instances directly through the multithreading mechanism provided by the .NET Framework or by wrapping multithreading with the Delegate class under the asynchronous architecture provided by the .NET Framework. These methods are to make a worker thread (Worker Thread) stop waiting for the result of execution in the background, and once there is a result, the worker thread will inform the result through the standard mechanism.

1. ADO.NET SqlConnection object

ADO.NET uses SqlConnection objects to connect to SQL Server. There are two common forms of connection strings:

1. Use Windows to integrate secure authentication, for example:

String connectionString = "IntegratedSecurity=SSPI;Database=MyDatabase.mdf;Server=localhost;"

Or:

String connectionString = "Initial Catalog= MyDataBase; Data Source=localhost;Integrated Security=SSPI;"

two。 Specify the server name, user id, user password, database name, and so on in the connection string. For example:

String connectionString = "server=localhost; uid=sa; pwd=123; database=MyDatabase.mdf"

Then create the SqlConnection object directly through the connection string, as shown in

SqlConnection conn = new SqlConnection (connectionString)

2. ADO.NET SqlCommand object

In ADO.NET, there are two ways to manipulate a database:

1. Connectionless mode

two。 The way to stay connected.

Either way, you can pass commands for database operations through the methods provided by the ADO.NET SqlCommand object and return the results of the command execution.

The general steps for operating a database while maintaining a connection are:

1. Create an instance of SqlConnection

two。 Create an instance of SqlCommand

3. Open the connection

4. Execute a command

5. Close the connection.

The ADO.NET SqlCommand object provides several ways to complete operations on the database. Commonly used are:

ExecuteNonQuery

This method executes the results of the SQL statement, but does not return the table data executed by the command, only the number of rows affected by the operation.

ExecuteReader

The ExecuteReader method provides a fast forward-only, sequential way to read data from a database. According to the provided SELECT statement, this method returns a SqlDataReader object that can be read sequentially, and the programmer can use the Read method to cycle through the contents of each field (column) in each record.

ExecuteScaler ()

This method is used to execute a SELECT query, and the returned result is a value, such as using the count function to calculate the number of records in the table or using the sum function to sum.

At this point, I believe you have a deeper understanding of "how to use ADO.NET SqlCommand objects". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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