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This article introduces the relevant knowledge of "what is the method of using ADO.NET database". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

The first thing to say is DBConnection, which is equivalent to establishing a path between the program and the database server, so without it, all operations on the database become empty talk. When operating on DBConnection objects, you should pay attention to the following points:

Set ConnectionString (connection string), which is like choosing the direction of the path. If the direction is wrong, the path cannot be established. The connection string settings are also different for different databases, as described below. ADO.NET database connection string:

SQL Server data source= database server name; initiacatalog= database name; user id= connection user name; password= password; Access Provider=Microsoft.JET.OLEDB.4.0; data source= database file name (indicates path); user id=Admin;Jet OLEDB:Database Password= password

Note: "Jet OLEDB:Database Password= password;" this part is optional, that is, if you do not have a password, you can remove this part.

Call the Open and Close methods to open and close the database connection, which is captured with TRY-CATCH because the database connection is abnormal. Use the State property to view the status of the current database connection. For example, if you do not operate the database for a period of time, the database connection is likely to be closed by the system, so in each database operation, * first judge the State attribute of the database connection, for example, in SQL Server:

If (sqlConn.State==ConnectionState.Closed | | sqlConn.State==ConnectionState.Broken) / / Connection is not available return false; else / / Connection is available return true

When the ADO.NET database can be connected is open, then carry out the database operation. Next, let's talk about the DBCommand class, through which all operations on the database are done. If DBConnection is compared to a passageway, then DBCommand is a vehicle running back and forth on that passageway. Without it, all operations on the database in the program cannot be passed to the ADO.NET database server. So it can be said that DBConnection and DBCommand form the basis of ADO.NET. When operating on the DBCommand object, you need to pay attention to the following points.

To set the CommandText and CommandType properties, it is generally not necessary to set the CommandType property, but if you execute a stored procedure, you need to set the CommandType property to StoredProcedure. It is recommended to use more parameters and reduce the concatenation of strings, so that you can reduce program writing errors and avoid sentence worms. Parameters can be used as follows:

SqlCommand myComm = new SqlCommand (); myComm.CommandText = "SELECT * FROM UserInfo WHERE UserName = @ UserName"; myComm.Parameters.Add ("@ UserName", yourValue)

Distinguish between the ExecuteNonQuery method and the ExecuteReader method, the former mainly deals with non-query type statements, and the number returned is affected, but it has no effect on the "INSERT" statement, while the latter mainly deals with query statements, but needs to be assisted by DataReader. Don't forget to call the Dispose method to release the DBCommand object after you finish using it.

This is the end of the content of "what is the method used in ADO.NET database". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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