1. Advanced Visual Basic 2005 4 th Edition Chapter 3: Using SQL Server Databases (c) 2007 Pearson Education Inc. All rights reserved. You may modify and copy this slide show for your personal use, or for use in the classroom, as long as this copyright statement, the author's names and title are not changed. Slides prepared by the authors Revision date: Jan 18, 2007 by Kip Irvine and Tony Gaddis

2. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 2 Overview Database Basics SQL SELECT Statement Using the DataGridView Selecting DataSet Rows Data-Bound Controls Karate School Manager Application

3. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 3 Database Basics

4. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 4 Introduction Database holds collection of tables Table is logical grouping of related information rows – each row holds a logical unit columns – similar to attributes Example:

5. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 5 Primary Key Column or columns that uniquely identify each row Can be any data type Can be auto-generated (identity) Departments table: dept_id column is the primary key

6. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 6 SQL Server Data Types Microsoft SQL Server.NET uses SqlDbType to identify data types

7. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 7 Designing Database Tables Database schema design of tables, columns, and relationships Choose descriptive column names Use data types that match the data values Sample Members table:

8. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 8 Sample Column Types Primary key – Int type Person's last name: VarChar type Salary: Decimal type Ratio: Float type Boolean (True/False): Bit type Birth date: DateTime or SmallDateTime type Picture: Image type

9. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 9 One-To-Many Relationship Relational model relations between tables minimizes duplication of data within table rows Primary Key referenced by Foreign Key Example:

10. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 10 Checkpoint 1.How is a table different from a database? 2.In a table of employees, what column would make a good primary key? 3.Which Visual Basic data type is equivalent to the Bit column type in SQL Server? 4.Why would we not want to spell out the name of each person’s department name in a table of employees? 5.How is a foreign key different from a primary key?

11. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 11 SQL SELECT Statement

12. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 12 SELECT Statement SQL – Structured Query Language Standardized by ANSI (American National Standards Institute) SELECT returns rows from one or more tables Example 1: SELECT ID, Salary FROM SalesStaff Example 2: SELECT [Last Name], [First Name] FROM Employees Example 3: SELECT * FROM SalesStaff

13. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 13 Setting the Row Order with ORDER BY Format: ORDER BY columnName [ASC | DESC] Examples: ORDER BY Last_Name ASC ORDER BY Last_Name ORDER BY Last_Name DESC ORDER BY Last_Name, First_Name Complete example: SELECT ID, Salary FROM SalesStaff ORDER BY ID

14. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 14 Selecting Rows with the WHERE Clause WHERE clause filters (selects) rows returned by the SELECT statement Simplest format WHERE columnName = value Example: SELECT First_Name, Last_Name, Salary FROM SalesStaff WHERE Last_Name = 'Gomez'

15. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 15 Relational Operators Operators permitted in WHERE clause expressions:

16. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 16 Numeric and Date Values Numeric literals have no delimiters or commas Parentheses are optional WHERE Salary > 30000 WHERE (Salary > 30000) DateTime values are delimited by single quotes WHERE (Hire_Date > '12/31/1999')

17. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 17 Checkpoint 1.Write a SELECT statement that retrieves the pay_rate, employee_id, and hours_worked columns from a table named Payroll, and sorts the rows in descending order by hours_worked. 2.Write a SELECT statement that creates an alias named Rate_of_Pay for the existing column named pay_rate in the Payroll table. 3.Write a SELECT statement for the Payroll table that creates a new output column named gross_pay by multiplying the pay_rate column by the hours_worked column. 4.Write a SELECT statement for the Payroll table that returns only rows in which the pay_rate is greater than 20,000 and less than or equal to 55,000. 5.Write a SELECT statement for the Payroll table that returns only rows in which the employee_id column begins with the characters FT. The remaining characters in the employee_id are unimportant.

18. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 18 Using the DataGridView

19. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 19 Introducing the DataGridView Displays data in rows and columns Usually bound to a DataTable User can add, edit, and delete rows Customizable (design time & run time)

20. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 20 Data-Related Components Data source connects to database or file containing data TableAdapter transfers data from data source to the application may also update the data source DataSet in-memory copy of data from the data source filled by TableAdapter BindingSource optional link between DataSet and bound controls

21. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 21 Formatting Columns in a DataGridView Select the Columns property DefaultCellStyle property Format property

22. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 22 Tutorial 3-1 Showing a database table in a DataGridView control SalesStaff table in the Company database

23. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 23 Tutorial 3-1 Configure the DataGridView tasks Add a new connection VS copies database into the project folder

24. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 24 Tutorial 3-1 (continued) Select the SalesStaff table Display in a DataGridView Fill the SalesStaff DataTable:

25. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 25 Checkpoint 1.Using the application you created in Tutorial 3-1, explain how to change the formatting of the Salary column so it displays values in currency format. 2.The technique called ________ links database tables to controls on Visual Basic forms. 3.Which component pulls data from one or more database tables and passes it into a DataSet? 4.When changes are made to a DataSet at runtime, what happens to the database that filled the DataSet? 5.Which control displays DataSets in a spreadsheet-like format? 6.What type of object connects a program to a database?

26. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 26 Selecting DataSet Rows

27. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 27 SQL Structured Query Language commonly used statements SELECT, DELETE, INSERT, UPDATE,... SELECT queries a database retrieves rows Updating a database INSERT DELETE UPDATE

28. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 28 Modifying the Query in a Data Source Locate DataSet's schema file in the Solution Explorer window open the DataSet designer tool: Use Query Builder:

29. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 29 Query Builder Diagram pane Grid pane SQL pane Results pane

30. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 30 Adding a SELECT Query to a DataGridView Right-click the TableAdapter icon select Add Query Search Criteria Builder window ToolStrip added to the form, containing a button

31. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 31 Tutorial 3-2 Filtering rows in the SalesStaff table Display results in a DataGridView Query:

32. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 32 Checkpoint 1.What does the acronym SQL represent, in relation to databases? 2.Why do SQL queries work with any relational database? 3.Write an SQL SELECT statement that retrieves the First_Name and Last_Name columns from a table named Employees. 4.How do you add a query to a TableAdapter in the component tray of a form? 5.Write a WHERE clause in SQL that limits the returned data to rows in which Salary is less than or equal to $85,000.

33. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 33 Data-Bound Controls

34. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 34 Describing Data-Bound Controls Automatically display the contents of the current table or table row Update their contents automatically when the user moves through rows in a DataSet Can update the contents of the DataSet

35. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 35 Visual Studio Copies Database Files When you attach an SQL Server database file Makes a local copy of the database Updates made at runtime only affect a temporary copy of the database saved in the \bin\Debug or \bin\Release folder replaced each time the program runs

36. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 36 Modifying a Connection String Right-click project name in Solution Explorer window select the Settings tab click the Browse button

37. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 37 Binding Data Source to DataGridView Existing data source Drag onto a form VS inserts a DataGridView and navigation bar

38. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 38 Binding Individual Fields to Columns Select Details in the table's dropdown list inside the Data Sources window Drag the table onto a form or drag individual columns onto the form select control binding type edit the fields as needed

39. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 39 Introducing the Karate Database Karate school management database Tables Members Payments

40. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 40 Binding Data Sources to ListBoxes and ComboBoxes DataSource property identifies the DataTable supplying the data DisplayMember property identifies the displayed column ListBox or ComboBox can be used as a navigation or selection tool BindingSource repositions itself to the selected row

41. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 41 Tutorial 3-3 Displaying the Members table in a ListBox add a new data source (Members table) attach it to the ListBox's DataSource property set the ListBox's DisplayMember property Run the application when user selects a last name, the member's detailed fields are displayed:

42. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 42 Adding Rows to DataSet Tables NewRow method creates and returns an empty row with same structure as the DataSet table: Dim row as DataRow = _ PaymentsDataSet.Payments.NewRow( Add method adds a row to the table pass it the column values pass Nothing for autoincrement columns PaymentsDataSet.Payments.Rows.Add(Nothing, _ 5, '5/15/2006', 50D)

43. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 43 Updating, Inserting, Removing Rows TableAdapter Update method writes changes to the underlying database PaymentsTableAdapter.Update(PaymentsDataSet) TableAdapter Insert method inserts a new row in a table PaymentsTableAdapter.Insert(5, '5/15/2006', 50D) DataRow Remove method requires a reference to a table row Dim row As DataRow = _ PaymentsDataSet.Payments.FindByID(36) PaymentsDataSet.Payments.Rows.Remove(row)

44. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 44 Tutorial 3-4 Inserting rows in the Karate Payments table uses DataGridView control calls the TableAdapter's Insert method

45. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 45 Using Loops with DataSets Iterate over the Rows collection of a DataTable For-Each loop Example, using the Karate Payments table:

46. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 46 Tutorial 3-5 Adding a total to the Insert_Karate_Payments application continues Tutorial 3-4 Click handler for the Total Payments button:

47. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 47 Checkpoint 1.Which Visual Studio window displays the list of data sources belonging to a project? 2.The ______ Configuration Wizard is a tool you can use to create a connection to a database and select a database table. 3.If a certain DataTable already exists, what is the easiest way to bind it to a DataGridView control? 4.How do you bind a single DataSet column to a text box? 5.By default, which control binds to a DateTime field in a DataSet? 6.What is the menu command for adding a new DataSet to the current project?

48. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 48 Karate School Manager Application

49. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 49 Features 1.Displays a list of all members 2.Permits the user to sort on any column, edit individual rows, and delete rows 3.Adds new students to the list of members 4.Finds a member by letting the user enter a partial last name 5.Displays payments by all members, sorting on any column 6.Displays a list of payments by one member

50. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 50 Main Form Starts the application File, Membership, and Payments menus

51. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 51 Membership Forms All Members Find Member by Last Name Add New Member

52. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 52 Payments Forms Payments by All Members sort on any column Payments by One Member select member from ComboBox

53. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 53 Tutorials 3-6 and 3-7 Tutorial 3-6 Creating the Karate School Manager startup form Tutorial 3-7 Listing all members

54. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 54 Using a BindingSource Connection between DataSet and the data-bound controls on a form updates the DataSet when user modifies data in bound controls Items collection BindingSource class methods and properties DataSource AddNew RemoveCurrent EndEdit CancelEdit

55. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 55 Tutorial 3-8 Karate School Manager: Adding new members Members table uses data binding writes changes to a temporary copy of database

56. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 56 Using Query Parameters Create simpler, more flexible SQL queries Avoid concatenating SQL statements to control names: Define parameter name with @ prefix: TableAdapter's Fill method has a new parameter: MembersTableAdapter.Fill( _ Me.FindMemberDataSet.Members, txtLastName.Text)

57. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 57 Wildcard Matches in SQL Queries Use the LIKE operator % matches any character string Example Returns all last names starting with letter G: WHERE Last_name LIKE 'G%'

58. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 58 Tutorial 3-9 Karate School Manager: Finding members by name accepts partial name string uses query parameter uses LIKE operator with wildcard matches

59. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 59 Tutorial 3-10 Karate School Manager: Listing payments by all members joins Payments, Members tables uses DataGridView control

60. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 60 Tutorial 3-11 Karate School Manager: Showing payments by one member user selects name from ComboBox payments shown in DataGridView

61. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 61 Checkpoint 1.In the Karate database, which table contains the names and dates when students joined the school? 2.In the PaymentsAllForm form, which two tables are required when filling the grid? 3.Which property of a DataGridView control lets you alter the order in which columns appear? 4.How does the PaymentsOneForm form obtain the ID number of the member selected by the user in the ComboBox? 5.What special keyword is used in the WHERE clause of a query when you want to perform a wildcard comparison?

62. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 62 Summary Database Basics SQL SELECT Statement Using the DataGridView Selecting DataSet Rows Data-Bound Controls Karate School Manager Application

63. Advanced Visual Basic 2005, 4 th Edition. © Pearson Education Inc. 63 The End