This chapter is about working with databases.
In this chapter we will:
With Web Pages, you can easily display data from a database.
You can connect to an existing database, or create a new database from scratch.
In this example we will connect to an existing SQL Server Compact database.
In the "DemoWebPages" folder, create a new CSHTML file named "Products.cshtml".
Replace the code in the file with the code from the example below:
The Database.Open(name) method will connect to a database in two steps:
First, it searches the application's App_Data folder for a database that matches the name parameter without the file-name extension.
If no file is found, it looks for a "connection string" in the application's Web.config file.
(A connection string contains information about how to connect to a database. It can include a file path, or the name of an SQL database, with full user name and password)
This two-step search makes it possible to test the application with a local database, and run the application on a web host using a connection string.
|Database.Execute(SQLstatement [, parameters])||Executes SQLstatement (with optional parameters) such as INSERT, DELETE, or UPDATE and returns a count of affected records.|
|Database.GetLastInsertId()||Returns the identity column from the most recently inserted row.|
|Opens either the specified database file or the database specified using a named connection string from the Web.config file.|
|Database.OpenConnectionString(connectionString)||Opens a database using the connection string. (This contrasts with Database.Open, which uses a connection string name.)|
|Database.Query(SQLstatement[, parameters])||Queries the database using SQLstatement (optionally passing parameters) and returns the results as a collection.|
|Database.QuerySingle(SQLstatement [, parameters])||Executes SQLstatement (with optional parameters) and returns a single record.|
|Database.QueryValue(SQLstatement [, parameters])||Executes SQLstatement (with optional parameters) and returns a single value.|