Unit 3 Data Access using GUI

1. Unit 3Data Access using GUI

2. Agenda • Data Sources • SQL Data Source • Displaying Data • GridView • DetailsView • Configuration Manager • Accessing Data

3. Data Sources • Embody a connection to a database • Location • Name • Contain an SQL command • Example: • SqlDataSource is used with MS SQL Server

4. SQL DataSource • It represents: • name and location of database • SQL command • Specific to MS SQL Server • Uses a wizard for configuration • Prefix: “sds”

5. Displaying Data • Two GUI controls used for displaying data: • GridView: shows all records • DetailsView: shows selected record • Need to be bound to a Data Source, such as • SQLDataSource • DataReader • Customizable • See note on Design in Unit 3.1 Step-By-Step

6. GridViews • Show all records of a dataset • Can do more than display • Paging • Sorting data • Insert, Update functions • Custom Template Fields

7. DetailsView • Show only a single record at a time • Supports inserting and updating similar to GridViews • Often paired with GridViews

8. Configuration Manager • Web applications need governing rule-sets • For login controls, web services, or databases • They exist as web.config files in ASPPub • For Databases  Connection Strings • Store path, database filename, database driver • Example: (Can you tell the “name” of the connection string?) <configuration> <connectionStrings> <add name="Products" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\SouthBreezeGroceries.mdf;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/> </connectionStrings> <other-web-service-stuff> </other-web-service-stuff> </configuration>

9. Accessing Data: Create a GridViewRow • GridViews are collections of rows. • So your code needs to loop through these rows • First, create an object of the type GridViewRow GridViewRowGrvCheck GridViewGrvOrders

10. Accessing Data: Setup the loop • Setup a loop to go through all rows • The FOREACH loop is a variation of the FOR loop • It can automatically cycle through rows. • For example: foreach (GridViewRowgrvCheck in grvOrders.Rows) { // do stuff for one row at a time // collect all data, do any totals }

11. Accessing Data: Working with cells • Each row has many columns, or cells. • Cells are indexed (counting from zero). • In the example below: • The first column, i.e. Column 0 is occupied by the Select button • The second column contains OrderID. Since indices begin at 0, the second column is accessed by the index of 1, as shown below: OrderID = Convert.ToInt32(grvCheck.Cells[1].Text); grvCheck.Cells[1].Text