Chapter 10: Working with Large Data Spreadsheet-Based Decision Support Systems Prof. Name Position (123) University Name

2 Overview  10.1 Introduction  10.2 Importing Data  10.3 Creating Pivot Tables from External Data  10.4 Using Excel as a Database  10.5 Summary

3 Introduction  Import data from a text file, webpage, or database.  Create pivot tables using data from an external database.  Sort and filter a database table in Excel.  Create “official” Excel Tables to store and analyze data.  Work with database functions in Excel.  Apply database validation and consolidation in Excel.

4 Importing Data  Text Files  Web Addresses  Databases

5 Importing Data  In many cases, an Excel user may not be given data in a worksheet to manipulate.  If this is the case, you can use Get External Data group of commands on the Data tab of Excel Ribbon to transfer this data to a worksheet where Excel analysis tools can be applied.  There are three sources from which you can import data into Excel –Text files –Web addresses –Databases

6 Text Files  To import data from a text file, use the Text Import Wizard.  Click on: Data > Get External Data > From Text command. You are then prompted to open a text file in Excel.  There are three steps to import text files using the wizard. –Step 1: Specify how the data will be organized –Step 2: Specify how to separate the data –Step 3: Apply particular numerical formatting

7 Figure 10.1  Consider a text file which records the number of hours ten employees worked during three consecutive weeks.  For each employee, the start date and hours worked are recorded.

8 Figure 10.2  Step 1: Specify that the text is delimited.

9 Figure 10.3  Step 2: Specify that the data is separated by tabs.

10 Figure 10.4  Step 3: Date formatting is applied to the “MDY” column.

11 Figures 10.5 and 10.6  The text has now been imported to Excel.  The employer can now use the Excel AVERAGE() function to compute the averages.

12 Web Addresses  To import data from a webpage, use the Data > Get External Data > From Web command on the Ribbon. –Enter the web address which contains the data you want to import. –Select what sections of data you want to import. –Click Import. –Select a cell in the worksheet for where you want this imported data to be placed.  The data will be imported there and separated into columns as done in the webpage.

13 Figure 10.7  The following web address contains current stock quotes reported by CNN:  Paste the web address into the “Address” window of the New Web Query dialog box.

14 Figures 10.8 and 10.9  The location of the import in the Excel workbook is specified.  The data is now imported into columns on a spreadsheet.

15 Figure  We can now further format this data for future analysis.  To repeat a query: –Select the range of queried data in the worksheet. –Click on: Data > Connection > Refresh All > Refresh command.

16 Databases  To import data from an Access database, click on: Data > Get External Data > From Access command on the Ribbon.  To import data from another database we click on: Data > Get External Data > From Other Sources command on the Ribbon.  Use Edit Query to modify some parts of a database already imported. –A query is a search for a particular set of data from our database, similar to filtering.

17 Import Data from Access  A database, titled Books, is created in Microsoft Access.  It keeps a record of books. These are the fields of the database: ISBN, Title, Author, and Copyright Year.  Click on: Data > Get External Data > From Access command.  Specify the location of the data imported.

18 Figure  The imported data is copied to the worksheet.

19 Import Data from Other Sources  Click on: Data > Get External Data > From Other Sources command.  Select From Microsoft Query from the drop-down menu.  Specify the type of database being used.

20 Figure  Select a file from the list of files which match the data source.

21 Figure  Select which columns of data should appear in the final table.

22 Figure  Define the query by filtering the data.

23 Figure  Specify how to sort the data in the final table.

24 Figure  Select to view the results of the query in Excel.

25 Figure  The imported data has now been modified after editing the query.

26 Creating Pivot Tables from External Data  Use the University database to create a table that summarizes the distribution of students by department, and gender. –Click on: Insert > Tables > PivotTable command. –Select Use an external data source from the Pivot Table Dialog Box. –Select a location for the pivot table in the existing worksheet. –Click Choose Connection to specify where the actual data is saved.

27 Figure  Select data source as a MS Access database with data for a University Information System.

28 Figure  Select one of the existing tables and queries of the selected database.

29 Figure  We can use the PivotTable Field List to build the pivot table.

30 Figure  Specify the layout and location of the pivot table and other options the (as was shown in Chapter 6) to complete the pivot table.

31 Using Excel as a Database  Sorting  Filtering  Excel Tables  DFunctions  Data Validation  Data Consolidation

32 Sorting  Sorting is the ordering of all entries in a database by a particular field, where a field is the name of a category.

33 Sorting  Highlight the entire database, including the field names, then click on the Data > Sort & Filter > Sort command on the Ribbon.  Sort dialog box appears:  The entire database is sorted by Student Name. Names are listed in an alphabetical order.

34 Figure  The table is now sorted by the students’ names.

35 Figure 10.28(a)  Sort the database by more than one field.

36 Figure 10.28(b)  The table is sorted by Class Averages in a Descending order, and by Student Names in an Ascending order.

37 Sorting Options  My data has headers option informs Excel whether or not column headers are included on the data set.  If we uncheck the My data has headers checkbox, there would only be column names in the field list.

38 Sorting Options  We can also sort within a row.  The field lists show row numbers instead of column numbers.

39 Figure  The table is now sorted by Row 4 on Z to A order.

40 Filtering  Filtering differs from sorting because it selects a specified set of data from the database instead of ordering the entire database.  Filtering allows us to select rows in a database by a specific value for one or more fields.  Highlight the entire database including column titles, then choose Data > Sort & Filter > Filter command on the Ribbon.  Drop-down arrows appear next to each field of the table.

41 Figure 10.33

42 Figure 10.34(a)  Use the filtered field drop-down menu to filter for a particular value in a selected field.

43 Figure 10.34(b)  The database is filtered to only display data entries that have a Class Average equal to 88.6.

44 Figure  On the filtered field drop-down menu, upon the selection of the Number Filters option, a flyout menu appears that presents a number of options we can use when filtering a database.

45 Figure  Use the Top 10 Items filter for the Class Average field.

46 Figure  Use the Custom filter on the Class Average field.

47 Excel Tables  Excel is designed to store data in a table.  A table is a range which contains data organized in rows and columns.  Each row and column has a heading to describe the content of the table.  To create a table: –Select a range of data. –Click on the Insert > Tables > Table command on the Ribbon.

48 Figure 10.38

 It is easy to add new columns and build calculated columns on Excel tables.  Calculate the average of the grades students made on their assignments. 49 Figure 10.39

 When a table is created using data from multiple sources, duplicated rows or columns of data may be created.  To remove duplicates, click on the Table Tools Design > Tools > Remove Duplicates command on the Ribbon. 50 Figure 10.40

51 DFunctions  There is a group of Excel functions which are tools specifically for working with Excel as a database; we call these functions Dfunctions.  These are specific functions designed for use with databases. They include –DSUM –DAVERAGE –DMIN –DMAX  Dfunctions differ from the previously described functions because they specify certain criteria before performing the function. –For example: =DSUM(database, field, criteria)

52 DFunctions (cont’d)  The criteria parameter is a range of cells that includes a cell or cells with a field name and a cell or cells below the field name with a specified criterion.  In preparation for using Dfunctions, we must add a few rows to our database. These rows contain our criteria and must repeat our field names.

53 Figure  Find the minimum Exam 2 score for students with a Class Average above 85.0.

54 Figure  Click on the Formulas > Function Library > f x Insert Function command from the Ribbon.  Find the function category labeled Database.  We can now view all of the Dfunctions and choose DMIN from the list.

55 Figure  The DMIN function is used as follows: –=DMIN(database, field, criteria) –=DMIN(B3:I20, G3, I21:I22)  We refer to the criteria specified in the additional rows below the table.

56 Figure  The DMIN function uses the criteria in the Class Average field and the criteria in the Attendance field.

57 COUNT Functions  Another group of functions, which are also useful to use with database data in Excel, are the COUNT functions.  In this group there are four main functions –COUNT –COUNTA –COUNTBLANK –COUNTIF

58 COUNT Functions (cont’d)  The COUNT function simply counts the number of cells with numerical values in a given range. –=COUNT(range)  The COUNTA function counts all of the cells with data of any kind in a given range of cells. –=COUNTA(range)  The COUNTBLANK function will count the number of blank cells in a given range. –=COUNTBLANK(range)  The COUNTIF function will count the number of cells in a given range which meet a specified criteria. –=COUNTIF(range, criteria)  The criteria can contain some helpful characters such as “*” for a sequence of unknown values or “?” as a single wild card value.

59 Figure  Using the COUNT, COUNTA, and COUNTBLANK functions

60 Figure  A COUNTIF example:

61 SUMIF Function  The SUMIF function will sum the values in a given range which meet a specified criteria. –=SUMIF(range, criteria, sum_range)  This function is also similar to the DSUM function we saw earlier in this section.  Even though it is used in the same manner in which the DSUM function is used, it only allows for single criteria.  Therefore, when using Excel as a database, we recommend using the DSUM function instead of the SUMIF function so as to handle multiple criteria.

62 Data Validation  Data validation enforces a certain format or type of data to be entered by the user for particular input. –To use data validation, select the cell(s) you want to validate and then click on Data > Data Tools > Data Validation command on the Ribbon.  There are three main tabs in this window: Settings, Input Message, and Error Alert.

63 Figure  There is a list of criteria including Whole Numbers, Dates, Text Lengths, and others.

64 Figure  Depending on which criteria are selected from the list, we will have a few more options to further specify these criteria.  For example, if we choose Whole Number from the list, we then choose from a list of inequalities and provide some numerical bounds.

65 Figure  The Input Message tab allows us to create a comment that will appear next to the cell after it is selected.  This message is intended to guide the user to enter the correct data.

66 Figure  The Error Alert allows us to display a message to the user if any data has been incorrectly entered.

67 Figures and  We have a record of customer orders. For each order, the date, quantity, and price of the order are noted.  Maximum of 5 products can be sold in any one order. –The Input Message for this validation appears when a cell in the Quantity column is selected. –The Warning Message created in the Error Alert tab will appear if we enter a number greater than 5.

68 Figures and  We could also validate the Date column in this example by choosing the Date criterion.  Choose the Information alert type.  The Input Message and alert are shown.

69 Figure  With the Custom criterion, the user applies a formula to the first cell in the selected range that is being validated.

70 Figures and  The List criterion allows us to create a list box, or drop-down box, of options for users to choose from as their entry value.  Then, we can set the Input Message and Error Alert so that the users know they can only enter one option from the provided list.

71 Data Consolidation  Data consolidation allows you to compare and combine multiple sources of data into a new spreadsheet. –Select Data > Data Tools > Consolidate command on the Ribbon to create the consolidated table.  Suppose that we have monthly sales recorded for various products in two different marketing regions.

72 Figure 10.59(a)

73 Figure 10.59(b)

74 Figures and  The data consolidation tool provides a list of functions that can be applied to the data as it is consolidated.  After selecting the function, we must choose the references of the data that we want to consolidate.

75 Figure  The consolidated table.

76 Summary  You can import text files, webpage information, and database tables into Excel using the commands listed in the Data > Get External Data tab on the Ribbon. Queries can be performed to data being imported from a database.  Pivot Tables can use external data, such as from databases, as their source.  Sorting and Filtering along with Dfunctions can be used on large data in Excel.  The “official” Excel Table makes the process of organizing and manipulating data easier.  Data Validation allows you to enforce a certain format or type of data to be entered by the user for particular input.  Data Consolidation compares and combine multiple sources of data into a new spreadsheet.

77 Additional Links  (place links here)