[电脑基础知识]Week - 14 LAB Database.ppt

SQL Server Display Data in Gridview Display Data in Gridview using System.Configuration; using System.Data.SqlClient; using System.Data; protected void Page_Load(object sender, EventArgs e) { SqlConnection con = new SqlConnection (ConfigurationManager.ConnectionStrings [bankConnectionString1].ConnectionString); con.Open(); SqlCommand cmd = new SqlCommand(“select * from student, con); cmd.CommandType = CommandType.Text; SqlDataAdapter da = new SqlDataAdapter(); da.SelectCommand = cmd; DataSet ds = new DataSet(); da.Fill(ds, student); this.GridViewDemo.DataSource = ds; this.GridViewDemo.DataBind(); } 4.7 Views A View is a Virtual Table. It is not like a simple table, but is a virtual table which contains columns and data from different tables (may be one or more tables). A View does not contain any data, it is a set of queries that are applied to one or more tables that is stored within the database as an object. Use of a View Views are used as security mechanisms in databases. Because it restricts the user from viewing certain column and rows. Views display only those data which are mentioned in the query, so it shows only data which is returned by the query that is defined at the time of creation of the View. The rest of the data is totally abstract from the end user. Creating a View CREATE VIEW SampleView As SELECT EmpID, EmpName FROM EmpInfo Create a View Display Data by Using View Display data by a View Work with Student Table Create a View and Display Data select * from student Create a View create view ViewStudent as select * from student; Run the View to see data select * from ViewStudent Select * from ViewStudent where SID = ‘s004’ Insert and Update Data in View select * from ViewStudent Insert Record into View insert into ViewStudent values (S006,SKS,India); Display the inserted data view select * from ViewStudent Update the View update ViewStudent SET Name = Sunny where SID = S006‘ Display the updated view select * from ViewStudent Differ