Session 8: Data Management

(with Stored Procedures)

Data Management (Using Stored Procedures)

What Is a Stored Procedure? Why Use Stored Procedures? Calling Stored Procedures Using Parameters

Input Parameters

Output Parameters

What Is a Stored Procedure?

A common data procedures that can be called by many Web applications

Programmatic access to a database Return records

Return value

Perform action

Client

SQL Server

Web Form

StoredProcedure

Web Server

Database

Why Use Stored Procedures?

Modular programming Distribution of work Database security Faster execution Reduces network traffic Provides flexibility

Calling Stored Procedures

Identify the stored procedure Set up the SelectCommand property of the DataAdapter

Run the stored procedure and store returned records

Dim daCategory As New SqlDataAdapter()daCategory.SelectCommand = New SqlCommand()daCategory.SelectCommand.Connection = conndaCategory.SelectCommand.CommandText = "ProductCategoryList"daCategory.SelectCommand.CommandType = CommandType.StoredProcedure

daCategory.Fill(ds, "Categories")

Example: Calling a Stored Procedure

Using Parameters

Identify the available parameters Input Output InputOutput ReturnValue

Include parameters in the parameters collection

or Include parameter values in the command string

Passing Input Parameters

Create parameter, set direction and value, add to the Parameters collection

Run stored procedure and store returned records

SqlParameter param = new SqlParameter ("@Beginning_Date", SqlDbType.DateTime);param.Direction = ParameterDirection.Input;param.Value = Convert.ToDateTime

(txtStartDate.Text);da.SelectCommand.Parameters.Add(param);

ds = New DataSet();da.Fill(ds, "Products");ds = New DataSet()da.Fill(ds, "Products")

param = New SqlParameter _ ("@Beginning_Date", SQLDbType.DateTime)param.Direction = ParameterDirection.Inputparam.Value = CDate(txtStartDate.Text)da.SelectCommand.Parameters.Add(param)

Using Output Parameters

Create parameter, set direction, add to the Parameters collection

Run stored procedure and store returned records

Read output parameters

param = New SqlParameter("@ItemCount", SQLDbType.Int)param.Direction = ParameterDirection.Outputda.SelectCommand.Parameters.Add(param)

ds = new DataSet()da.Fill(ds)

iTotal = da.Parameters("@ItemCount").Value

Example: Passing Parameters