By Susan L. Miertschin. Separate the data access logic from the presentation layer

Transcription

1 Parameterize a Query By Susan L. Miertschin 2003 by The McGraw-Hill Companies, Inc. All rights reserved. Review - Data Access Layer Separate the data access logic from the presentation layer Open a Web Site Worked on Last Class We added a DataSet named staffinfo (or something along those lines) to new web site Inside the DataSet we dragged five related tables and a view and created retrieval methods for an list of staff members 3 1

2 Or -Open a New Web Site Open Visual Studio File New Web Site Rename Default.aspx to start.aspx Fix it so that t A Simple Example of ntier Data Access displays in the title bar of the browser at run time Fix the web.config file so that we can see error messages and we turn off Windows Authentication Develop locally on usb When complete: publish to icnn web folder 4 Connect to the Database with Visual Studio s Server Explorer View - Server Explorer You may already have a data connection to the class FC database that uses WebUser as the logon id for the SQL Server If you have this connection, use it Otherwise - create a new data connection that uses WebUser as the logon id for the SQL Server Save the password in the connection string; it is WebUser 5 Class SQL Server Cot-itec cougarnet.uh.edu,27930 Logon id: WebUser Password: WebUser 2

3 Connection String Specifications for the Class SQL Server Use SQL Server authentication NOT Windows authentication Login id: WebUser Password: WebUser Save the password in the connection string You would not do this in real life 7 Data Connection in Visual Studio You can see Tables Views Stored procedures User-defined functions 8 End of Review - Data Access Layer DAL 3

4 Explore Your Project From Last Class Hopefully you can access it otherwise you need to recreate it partially at least see next 10 What We Have At This Point (p. 1) A Typed DataSet named staff_info It has Table Adapters for each of these tables staff_t staff_phones_t staff_contacts_t phone_type_t contact_type_t 11 What We Have At This Point (p. 2) A Typed DataSet named staff_info It has a Table Adapter for a view that is created from these tables staff_t staff_phones_t staff_contacts_t phone_type_t contact_type_t 12 4

5 What We Have At This Point (p. 3) A strongly typed DataAdapter class accessible with IntelliSense Maybe something like the following: StaffContactInfoTableAdapters.StaffContactInfo TableAdapter 13 My DataSet TableAdapters, For Example 14 WHAT WE HAVE AT THIS POINT (P. 4) GridView controls onto the Default.aspx page with three or so lines of code each to populate them with data from the various table adapters POPULATES A PAGE WITH DATA RETURNED FROM THE METHODS OF THE TABLE ADAPTERS AT RUN TIME 15 5

6 IntelliSense Helps with Data Object Names Write 3 lines of code in the PageLoad event to retrieve data with the GetStaffContactData method and display it in a GridView control Dim staffinfota As New staff_infotableadapters.staffcontactinfotab leadapter GridView1.DataSource = staffinfota.getstaffcontactdata GridView1.DataBind() What you named the.xsd 16 Now We Will Add some Methods EXPAND FUNCTIONALITY 17 Add Several Methods to a staffinfo TableAdapter Right click on the TableAdapter for the staff_t table Add Query Use SQL Statements Write parameterized SELECT statements to retrieve staff members Who were hired before a certain date Whose last name starts with a particular pattern of letters With a particular title (number) 18 6

7 Select Staff Hired Before a Certain Date SELECT list all fields FROM dbo.staff_t WHERE hire_date_sd 19 Select Staff with a Particular Letter Pattern that Starts Their Last Name SELECT list all fields FROM dbo.staff_t WHERE last_name_vc 20 Select Staff with a Particular Title SELECT list all fields FROM dbo.staff_t WHERE title_in 21 7

8 Create both Types of Methods for Each Query Methods that return a DataTable getstaffbyhdate getstaffbyletters getstaffbytitleno Methods that fill a DataTable with data FillStaffByHDate FillStaffByLetters FillStaffByTitleNo 22 Add a New Page ParamterizedQueries.aspx Add three gridview controls 23 Code Page_Load Event (more or less) Dim staffinfota As New StaffInfoTableAdapters.staff f ff_ ttableadapt er GridView1.DataSource = staffinfota.getdatabyhdate( 10/01/2006) GridView1.DataBind() 24 8

9 Parameterize a Query By Susan L. Miertschin 2003 by The McGraw-Hill Companies, Inc. All rights reserved. 9