Stored Procedures Dr. Ralph D. Westfall May, 2009

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 or program in a database

SQL Server Stored Procedures precompiled in SQL Server so they run faster can be reused to avoid recoding make code simpler like subprocedures do better security can give users access to data from stored procedures rather than to whole tables

Stored Procedures code to manipulate database (retrieve data, add, change, delete) stored in database like subroutine, can use in multiple programs (but not with Access database) less storage: once instead of multiple copies easier to update than multiple copies stored queries run faster inside database makes it easier to migrate applications to other platforms or scale up to larger volumes

Stored Procedures with VB create or open a Visual Basic project Data>Add new Data Source to get an existing SQL Server database and select the tables that you will use View>Server Explorer expand the database you want, right-click Stored Procedures>Add New Stored Procedure

Configure Stored Procedure change name in top line us/library/aa258259(SQL.80).aspx us/library/aa258259(SQL.80).aspx r/a/storedprocedure.htm r/a/storedprocedure.htm

Create Stored Procedure right-click Stored Procedures>New Stored Procedure

Stored Procedures with VB start SQL Server Management Studio Express attach or create a database file right-click database name>New Query paste in a sample query (e.g., from link above) and modify it to match fields in this database) run it to see results

Creating Stored Procedures start SQL Server Management Studio expand a database>expand Programmability>right-click Stored Procedures>New Stored Procedure click Query in top menu>Specify Values for Template Parameters replace values for Datatypes and Default Values

Complete Stored Procedure replace SELECT statement with SQL code for the procedure parameters usually are in WHERE clause WHERE [field] e.g., WHERE AGE use Query>Parse to verify syntax click !Execute button to compile it File>Save (rename it)>Save

Verify Stored Procedure click Refresh icon in Object Explorer expand [database name]> Programmability>Stored Procedures to verify that it's there

Test Stored Procedure click New Query and type the following: USE "database name"; 'within quotes GO EXECUTE [stored proc = = [value2]; GO ignore warnings click !Execute button and verify results

Sample Code uses Nations.mdf database from Classy ProjectClassy stored procedure is named dbo.GetByPopGolds SELECT * from nations2 where Pop and Gold

Add Procedure to Code create a VB Project with a ListBox, two Textboxes and a Button double click the Button to create a Sub and add code on following pages

Declarations Dim sqc As SqlCommand Dim da As SqlDataAdapter Dim ds As DataSet Dim con As SqlConnection Dim dr As DataRow Dim output As String Dim pads() As Integer = {4, 22, 3, 3, 3, 7, 15} Dim padDirection() As String = {"L", "R", "L", "L", "L", "L", "R"}

Connection Code ds = New DataSet con = New SqlConnection con.ConnectionString ="server=.\SQLEXPRESS;" _ & AttachDbFilename=[path]\Nations.mdf;" _ & "Integrated Security=True;"

Getting Data sqc = New SqlCommand sqc.CommandText = "Exec [dbo].[GetByPopGolds] " _ & TextBox1.Text & ", " & TextBox2.Text sqc.Connection = con da = New SqlDataAdapter da.SelectCommand = sqc da.Fill(ds) ListBox1.Sorted = True

Load Outputs For Each dr In ds.Tables(0).Rows output = "" For i As Integer = 0 To 6 If padDirection(i) = "L" Then output += CStr(dr(i)).PadLeft(pads(i)) & " " Else output += CStr(dr(i)).PadRight(pads(i)) End If Next ListBox1.Items.Add(output) Next

Using Optional Parameters Optional Parameters in SQL Stored Procedures Optional Parameters in SQL Stored Procedures create a stored procedure based on the code at the above web page right click the stored procedure name> Execute Stored Procedure>either check Pass Null Value or input the desired criterion (don't do both!), OK and review output

Dynamic SQL include SQL code in parameters rather than just values potential security risks (SQL injection) potential to create more flexible stored procedures more options

Microsoft Access can create stored procedures in VB code ccess_sp.aspx ccess_sp.aspx

Creating a Stored Procedure download sample.mdb into the project foldersample.mdb create a query using design view can also use query from form or report see Help on saving SQL statements as queries use Save As to save query within the database with the name you give it

Additional Activity try to modify code to run the Query that you created in the database