DD Class9

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review Bios and Logon

Contents 1 Logon 1.1 Sessions 2 Review ADO 3 Simple ADO Binding 4 Inserting Editing Deleteing With ADO 5 Homework

Logon

Insert into the People Table

 
INSERT INTO People 
(salutationID, firstName, lastName, logonName, passwd)
	VALUES
(1, 'jeff', 'meyers', 'jmeyers', 'monkey')

Check the new users PeopleID

 
SELECT PeopleID FROM People WHERE firstName = 'jeff' AND lastName='meyers' AND logonName='jmeyers'

results PeopleID = 1

Give the new user a Role by inserting the PeopleID and a roleID into the roles table

 
INSERT INTO roles
( PeopleID, roleTypeID, RoleActive )
	VALUES
( 1, 1, 1)

 Note that we need two INSERT statements to create a working account and role. Since these two statements
depend on each other and we will be left with an Person without a role or a role without a person if one 
statement fails the entrire operation should be wrapped in a transaction. More on this next week...

Now we have a user and that user has a role. We need to be able to read back the userName, passowrd, roleActive and roleTypeName in order to check if a user is valid.

The easiest way to do this is with a view

 
SELECT dbo.people.peopleID, dbo.people.firstName, dbo.people.lastName, dbo.people.logonName,
       dbo.people.passwd, dbo.peopleSalutationTypes.salutationID, 
       dbo.peopleSalutationTypes.salutation, dbo.roles.roleActive, dbo.roleTypes.RoleTypeID,
       dbo.roleTypes.RoleTypeName, dbo.roleTypes.RoleTypeHier, 
       dbo.roleTypes.roleTypeActive
FROM dbo.people 
INNER JOIN
       dbo.peopleSalutationTypes ON dbo.people.salutationID = dbo.peopleSalutationTypes.salutationID 
INNER JOIN
       dbo.roles ON dbo.people.peopleID = dbo.roles.PeopleID 
INNER JOIN
       dbo.roleTypes ON dbo.roles.RoleTypeID = dbo.roleTypes.RoleTypeID

Now we can use the view to test a logon SELECT statement

 
SELECT peopleID, firstName, lastName, logonName, passwd, salutationID, 
       salutation, roleActive, RoleTypeID, RoleTypeName, RoleTypeHier, 
       roleTypeActive
FROM logon_vw
WHERE  
	logonName = 'jmeyers' AND
	passwd = 'monkey' AND
        roleActive = 1 AND
	roleTypeActive = 1

Now that we have the DataBase working correctly we can move on to the c#

Sessions

Every web application has a collection of objects called a session. Each browser is assigned a unique cookie that is used to identity the SessionID of the connection.

The session collection can hold any object and remain until a session times out. A session times out when the web server does not receive a request from a client for longer than the timeout period (deafult 20 mins)

session variables are set just like any other Collection. When you retrive an item form the collection you need to cast it back to it's original type (string casts are implict in c# so you really don't have to cast a string).

 
Session["LogonName"] = "test";
 
string strLogonName = (string)Session["LogonName"];

Review ADO

• Connection - used to connect the data consumer ASP.NEt to a Data Provider
• Command - used to issue SQL commands to a Data Provider
• DataReader - A fast forward only DataSet that holds one or more resultsets.Fast and efficient
• DataSet - can contain multiple tables and relationships between tables
• DataAdapter - Passes Data from a Connection object to a DataSet and updates that data. ( A bridge used to fill dataSets with DataAdapter.Fill and DataAdapter.Update)
• DataTable - structure that holds a set of rows and columns
• DataRelation - holds relations between DataTables in a DataSet
• DataRow - data within data row
• DataView - a specific view of the DataTables within a Dataset

Template:ADO.NET Diagram

Simple ADO Binding

 
//Connection string comes from web config
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["IamConnectionJeff"].ConnectionString);             
        
        string strSQL = "Select * from Course";  
        
        SqlCommand dc = new SqlCommand(strSQL , conn);
        SqlDataAdapter da = new SqlDataAdapter(dc);
        DataSet ds = new DataSet();
        DataTable dt = new DataTable();
        
        da.Fill(ds, "Course");          //Use the DataAdapter to fill the DataSet with a named Table
        dt = ds.Tables["Course"];       //Retreive the named table from the DataSet
        
        gvTestOrig.DataSource = dt;     //Set the DataTable as the source for the GridView noe AutoGenerateColumns = true
        gvTestOrig.DataBind();          //Bind the data form the table to the GridView

The above code binds to a control called gvTestOrig

 
 <asp:GridView ID="gvTestOrig" runat="server" AutoGenerateColumns="true" />

http://iam.colum.edu/dd/classsource/class8/SimpleADO.aspx - source

Same code but I moved some of the code into a function and split the declareation and initialization of some object to that they are scoped to the page not to Page_Load. This allows other functions on the page to use these objects.

http://iam.colum.edu/dd/classsource/class8/ADOTest1.aspx - source

Inserting Editing Deleteing With ADO

Add to a DataTable

 
        DataTable dt = ds.Tables["Course"];
        DataRow dr = dt.NewRow();
        dr["CourseName"] = "Applcations Design";
        dr["CourseNumber"] = "36-3601";
        dt.Rows.Add(dr);

Modify and DataTable

 
        DataTable dt = ds.Tables["Course"];
        DataRow dr = dt.Rows[3];            //Hack hard coded index
        dr["CourseName"] = "Application Design";
        dr["CourseNumber"] = "36-4601";

Delete from a DataTable

 
        DataTable dt = ds.Tables["Course"];
        DataRow dr = dt.Rows[1];            //Hack hard coded index
        dt.Rows.Remove(dr);

There are better method to select which row to modify see the example below

http://iam.colum.edu/dd/classsource/class8/ADOTest2AddModifyDelete.aspx - source

notice that changes made to the DataSet are not synchronized back to the Data Provider. 
The DataAdapter is able to sync these changes, remeber that the DataAdapter acts as a bridge between the 
DataSet and the DataProvider.

The DataAdapter can use the SqlStringBuilder class to create select, update, and delete statements. Once these statements are built the DataAdapter can update the DataProvider.

 
//Uses an SqlBuilder to update the DataAdapter also displays the generated sql in a lable
    public void CommitChanges()
    {
        //Get a stringBuilder from out DataAdapter
        SqlCommandBuilder cb = new SqlCommandBuilder(da);
        da.UpdateCommand = cb.GetUpdateCommand();
        lblUpdateCommand.Text = da.UpdateCommand.CommandText;   //Display the update Command in a Label
        da.Update(ds.Tables["Course"]);         //User tha DataAdpater to update the Data Provider
    }

http://iam.colum.edu/dd/classsource/class8/ADOTest3Commit.aspx - source

Homework

1 Build a page that demonstrates a single table update with ADO,

2 Write a proposal for final project the proposal should include

Proposal Template: http://iam.colum.edu/janell/edu/wi/docs/proposal_wi.rtf

Proposal Template (pdf): http://iam.colum.edu/janell/edu/wi/docs/proposal_wi.pdf

• Purpose
• Objectives
• Audience

• Website Scope
  • Simple map of web site(can be on paper or hyperlinks)
  • Number of web pages
  • Function of web pages
• DataBase Design
  • Mock up of tables and relations
  • ERD on paper or diagram in sql