【正文】 ify an existing data tables, storage, process or view, the doubleclick to. This will be their call to the Visual Studio in this you can modify it according to need. You can also observe and modify data in a single table of data and this is through a data table rightclick and choose data tables show data to achieve. Third, add a database to App_Data folder In addition to data connectivity options cards add to existing databases, you can also add a sitespecific database to the site39。s App_Data folder. App_Data is a new and retained in in the folder it was designed to store data on the content, including SQL database files (. Mdf file), Access database files (. Mdb file), XML documents. works from a site, you can easily create and add a new SQL Server 2020 Express database to your project Solution Explorer by rightclicking in the App_Data folder and choose Add New Item. Then, from the Add New Item dialog (shown below), select Add a new SQL database. If you want to follow the field), Name, City, State and ZipCode. Then, add some VS 2020 to record this data sheet. In addition, you can add existing Access database file or even SQL Server 2020 database files. (Note: To add an existing SQL Server 2020. Mdf file, you will need to make sure it is the first time from enterprise management on a separation。 To this end, Enterprise Manager, rightclick the name of the database, then select All Tasks and Select Detach database. Once you leave the subdatabases and add it to works, you can enterprise management for its reattachment.) Fourth, the SqlDataSource control connected to the database Now, since we have seen how to create and Visual Studio through the use of the interface to the database。 Below, let us turn their attention to from a visit to web pages from a database and display the data. includes several new data source controls their sole purpose is to provide data to the statement of access. There are five builtin data source control all of them in Visual Studio in the toolbox for section found. ? SqlDataSourcefor retrieval and modification of a relational database from the data. Here the Sql does not mean that the source of such data only with Microsoft SQL Server to work but can a relationship with any other database to work together: SQL Server, Access, Oracle, and so on. If you connect to a SQL Server database, then the controls will be very smart in the internal opening SqlClient category. ? AccessDataSourcefor retrieval and modification from an Access database files of data. You may want to know if the SqlDataSource and Access database file s can work together, then why is there this control 187。 In fact, this Access data source controls make it easier for you to connect to an Access database assigned to you as long as the Access database. Mdb file path. Note the use of SqlDataSource, you need to use a fully qualified to provide the specified data connection string. ? ObjectDataSourceto the adoption of a mercial object to retrieve and modify data. Ideally, your applications, including a group category it39。s a middle layer ( page rather than to direct operation of the database). If you have such a structure, you can use to query the middle of the ObjectDataSource. ? XmlDataSourcefor retrieval from an XML file data. ? SiteMapDataSourcedefinition used to provide readonly access to the site map in the structureof the site. In this control when you want in a TreeView or Menu control of the site shows a structure of use. In this article, we will only discuss Sql data source controls, and only of its basic features. First, let us add a Sql data source controls to your pages. From the design view, Sql data source controls include a sensitive labels it listed its mon features. The Configure Data Source sensitive labels link will activate a wizard it will guide you step by step through the entire process of configuration data sources. This wizard there are three main steps (and an optional substeps): 1. Choose your data connection the first step, we need to specify what connected to the database. This screen contains the App_Data folder database and a dropdown list in the data connectivity options card in a dropdown list. There is also a New Connection button you can click on it, if you want to connect to a location outside one of these in the database. If you continue, you can choose from the dropdown list box options. a) substeps: If this is your first time to add the link, you will be promp