1. Stored Procedures
Dr. Ralph D. Westfall
May, 2011

2. Getting Database Data
when using a database, there are two places where a detailed request for data can be located
inside a program that is separate from the database
inside the database itself
a stored procedure is a previously created query/command in a database

3. Stored Procedures code to manipulate database
work with data (data manipulation)
manage tables (data definition)
precompiled to run faster
better security
can give users access to data from stored procedures rather than to whole tables

4. Similarities with Subroutines
can be reused to avoid recoding, make code simpler, avoid redundancy, reduce resource requirements
easier to update than multiple copies
can be used in more than one program
easier to migrate applications to other platforms or scale up to larger volumes

5. Stored Procedures with SQL Server Management Studio
Click New Query button to create
SSMS doesn’t always seem to work if don’t qualify table and field names
Putting square brackets around field and table names may also help
Right-click a table name>Select Top 1000 Rows to see syntax punctuation
Or refresh Intellisense: [Ctrl]+[Shift]+[R]

6. Start a New Query
open SQL Server Management Studio and attach the table in OlyNations_Data.zip (OlyNations)
select it and click New Query in toolbar
type SELECT and drag/drop Columns icon from dbo.nations2 and dbo.currencies Tables after SELECT (add comma between groups, and then delete duplicate CID)

7. Database Names in a new line, type the word FROM
drag icons for tables (dbo.nations2 and dbo.currencies) and drop them after the from in the query (separate them with a comma)
copy these database table names and paste them before any fields that have the same names in both tables ("Ambiguous column names"), using a dot as a connector
start a new line after table names (Enter)

8. Where Clause type the word WHERE in the new line
paste table names from previous line after FROM
replace the comma with =
put a dot (.) after each table name and paste field name (CID) after each table name
click the Execute button in Toolbar
fix errors if necessary
save query with appropriate name for future use

9. Stored Procedure from Query
Under name of database, expand Programmability
right-click Stored Procedures
right-click Stored Procedures>New Stored Procedure
in CREATE PROCEDURE line, change <Procedure Name etc. > to what you want to call it

10. Parameters add parameters with the form of:
@[name] as [datatype] = null [or default], [next parameter] e.g.,
@country as char(25) = null [or 'Chile'],
@golds as int = null, [comma separated]
@pop as decimal(7,2) = null [or 3.2]
get datatypes from Columns definitions
default values can help with testing

11. Add Query
replace SELECT < etc. > with the query you created earlier
add a parameter based selection after the where clause (or make it be the where clause) e.g., and Country

12. Compile click Execute button
fix errors if necessary
close query builder window and save file with a filename that identifies it as creating this stored procedure
refresh Object Explorer and verify that stored procedure was created
Rename it to start with usp_

13. Testing a Stored Procedure
Put database name, stored procedure name, parameter argument(s) into a new query as follows:
USE OlyNations; GO
EXECUTE dbo.uspGetAll @pop = ;

14. Modifying Stored Procedures
right click the stored procedure name in SQL Server Management Studio>Modify
change code as necessary and then click Execute button to store it in the database
close the code window and save the code with a filename that identifies it as modifying this stored procedure

15. Using Stored Procedures in VB
create or use a VB project that works with a database
in a multi-tier application, most of the changes will be in the data tier
but business rules tier will have to be changed to provide parameters rather than SQL strings

16. Coding the VB Project
add a ComboBox to select countries, a ListBox for outputs and a Button to trigger selections
download and unzip OlySQLppt.zip
Project>Add Existing Item>select DT2.vb from subdirectory of file you just unzipped

17. Modify Data Tier Code
AcquireData Function receives a parameter value rather than SQL string
declarations
SQLCommand is stored procedure
SqlParameter is one of the parameters in the stored procedure
Dim sqlCmd As SqlCommand
Dim sqlParm As SqlParameter

18. More Added Data Tier Code
add the following after the statement that opens the connection [con.Open()]
sqlCmd = New SqlCommand()
sqlCmd.Connection = con
sqlCmd.CommandType = _ CommandType.StoredProcedure
sqlCmd.CommandText = "GetNations"

19. Even More Data Tier Code
rest of added block
sqlParmCountry = New _ selection)
sqlParmCountry.Direction = _ ParameterDirection.Input
sqlParmCountry.DbType = DbType.String
sqlCmd.Parameters.Add(sqlParmCountry)

20. Test Code
run it and debug as necessary

21. Multiple Parameter Selection
modify stored procedure to make all parameters default to null
make query ignore missing parameters
change 1st parameter selection:
and is null OR Country
additional parameters in same pattern
'notes
select ID, Country, Gold, Silver, Bronze, Pop,
Capital, dbo.currencies.CID, Currency
from dbo.nations2, dbo.currencies
where dbo.nations2.CID=dbo.currencies.CID
and is null OR Country
and is null OR Gold
and is null OR Pop

22. User Interface Modifications
declare each selection and assign selected value or default
If ComboBox1.SelectedIndex >= 0 Then
contry =
ComboBox1.SelectedItem.ToString()
Else
contry = "none"
End If

23. UI Modifications - 2 provide error message if no selections are made
If [ ]= "none" And [ ] = "none" Then
MsgBox("Select [ ] or [ ], or both")
Else …
[previous line of code to call data tier, modified to handle more arguments

24. Data Tier Modifications
modify Function to handle additional argument(s)
wrap 1st parameter block in If structure
If contryName <> "none" Then
add an If structure for the next parameter
see complete project code

25. DataGridView Using Stored Procedure
'notes
Private Sub FillToolStripButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FillToolStripButton.Click
Dim parmCountry As String
Dim parmGolds As Integer
Dim parmPop As Decimal
If CountryToolStripTextBox.Text = Nothing Then
parmCountry = Nothing
Else
parmCountry = CountryToolStripTextBox.Text
End If
If GoldsToolStripTextBox.Text = Nothing Then
parmGolds = Nothing
parmGolds = CInt(GoldsToolStripTextBox.Text)
If PopToolStripTextBox.Text = Nothing Then
parmPop = Nothing
parmPop = CDec(PopToolStripTextBox.Text)
Try
Me.UspGetAllTableAdapter.Fill(Me.OlyNations_DataDataSet.uspGetAll, parmCountry, parmGolds, parmPop)
Catch ex As System.Exception
System.Windows.Forms.MessageBox.Show(ex.Message)
End Try
End Sub

26. Stored Procedure
Pretty lengthy example using stored procedures. How Do I: Understand Data?
Visual Basic programmers will explore how connecting data in a database to controls in Windows Forms applications really works by looking deeper into the DataSet, BindingSource and TableAdapter objects and walking through examples of using data in code.

27. Or Use Designer for Query
right-click database name>New Stored Procedure then click Query>Design Query in Editor
select tables you want to use>Add>Close
select columns you want>OK