Chapter 34. Introducing Pivot Tables

IN THIS CHAPTER

An introduction to pivot tables

Types of data appropriate for a pivot table

Pivot table terminology

How to create pivot tables

Pivot table examples that answer specific questions about data

The Pivot Table feature is perhaps the most technologically sophisticated component in Excel. With only a few mouse clicks, you can slice and dice a data table in dozens of different ways and produce just about any type of summary you can think of.

If you haven't yet discovered the power of pivot tables, this chapter provides an introduction, and Chapter 35 continues with many examples that demonstrate how easy it is to create powerful data summaries using pivot tables.

34.1. About Pivot Tables

A pivot table is essentially a dynamic summary report generated from a database. The database can reside in a worksheet (in the form of a table) or in an external data file. A pivot table can help transform endless rows and columns of numbers into a meaningful presentation of the data.

For example, a pivot table can create frequency distributions and cross-tabulations of several different data dimensions. In addition, you can display subtotals and any level of detail that you want. Perhaps the most innovative aspect of a pivot table is its interactivity. After you create a pivot table, you can rearrange the information in almost any way imaginable and even insert special formulas that perform new calculations. You even can create post hoc groupings of summary items (for example, combine Northern Region totals with Western Region totals). And the icing on the cake: With a few mouse clicks, you can apply formatting to a pivot table to convert it into an attractive report.

One minor drawback to using a pivot table is that unlike a formula-based summary report, a pivot table does not update automatically when you change information in the source data. This drawback doesn't pose a serious problem, however, because a single click of the Refresh button forces a pivot table to update itself with the latest data.

Pivot tables were introduced in Excel 97. Unfortunately, many users overlook this feature because they think it's too complicated. The pivot table feature was improved significantly in Excel 2007, and you'll find a few new twists in Excel 2010. Creating and working with pivot tables is easier than ever.

34.1.1. A pivot table example

The best way to understand the concept of a pivot table is to see one. Start with Figure 34.1, which shows a portion of the data used in creating the pivot table in this chapter.

Figure 34.1. This table is used to create a pivot table.

This table consists of a month's worth of new account information for a three-branch bank. The table contains 712 rows, and each row represents a new account. The table has the following columns:

• The date the account was opened

• The day of the week the account was opened

• The opening amount

• The account type (CD, checking, savings, or IRA)

• Who opened the account (a teller or a new-account representative)

• The branch at which it was opened (Central, Westside, or North County)

• The type of customer (an existing customer or a new customer)

The bank accounts database contains quite a bit of information. In its current form, though, the data doesn't reveal much. To make the data more useful, you need to summarize it. Summarizing a database is essentially the process of answering questions about the data. Following are a few questions that may be of interest to the bank's management:

• What is the daily total new deposit amount for each branch?

• Which day of the week accounts for the most deposits?

• How many accounts were opened at each branch, broken down by account type?

• What's the dollar distribution of the different account types?

• What types of accounts do tellers open most often?

• How does the Central branch compare with the other two branches?

• In which branch do tellers open the most checking accounts for new customers?

You can, of course, spend time sorting the data and creating formulas to answer these questions. But almost always, a pivot table is a better choice. Creating a pivot table takes only a few seconds, doesn't require a single formula, and produces a nice-looking report. In addition, pivot tables are much less prone to error than creating formulas. (Later in this chapter, you'll see several pivot tables that answer the preceding questions.)

Figure 34.2 shows a pivot table created from the bank data. This pivot table shows the amount of new deposits, broken down by branch and account type. This particular summary represents one of dozens of summaries that you can produce from this data.

Figure 34.3 shows another pivot table generated from the bank data. This pivot table uses a drop-down Report Filter for the Customer item (in row 1). In the figure, the pivot table displays the data only for Existing customers. (The user can also select New or All from the drop-down control.) Notice the change in the orientation of the table? For this pivot table, branches appear as column labels, and account types appear as row labels. This change, which took about five seconds to make, is another example of the flexibility of a pivot table.

Figure 34.2. A simple pivot table.

Figure 34.3. A pivot table that uses a report filter.

34.1.2. Data appropriate for a pivot table

A pivot table requires that your data is in the form of a rectangular database. You can store the database in either a worksheet range (which can be a table or just a normal range) or an external database file. And although Excel can generate a pivot table from any database, not all databases benefit.

Generally speaking, fields in a database table consist of two types:

• Data: Contains a value or data to be summarized. For the bank account example, the Amount field is a data field.

• Category: Describes the data. For the bank account data, the Date, AcctType, OpenedBy, Branch, and Customer fields are category fields because they describe the data in the Amount field.

A single database table can have any number of data fields and category fields. When you create a pivot table, you usually want to summarize one or more of the data fields. Conversely, the values in the category fields appear in the pivot table as rows, columns, or filters.

Exceptions exist, however, and you may find the Excel Pivot Table feature useful even for databases that don't contain actual numerical data fields. Chapter 35 has an example of a pivot table created from non-numeric data.

Figure 34.4 shows an example of an Excel range that is not appropriate for a pivot table. You might recognize this data from the outline example in Chapter 26. Although the range contains descriptive information about each value, it does not consist of normalized data. In fact, this range actually resembles a pivot table summary, but it is much less flexible.

Figure 34.4. This range is not appropriate for a pivot table.

Figure 34.5 shows the same data, but normalized. This range contains 78 rows of data — one for each of the six monthly sales values for the 13 states. Notice that each row contains category information for the sales value. This table is an ideal candidate for a pivot table, and contains all information necessary to summarize the information by region or quarter.

Figure 34.5. This range contains normalized data and is appropriate for a pivot table.

Figure 34.6 shows a pivot table created from the normalized data. As you can see, it's virtually identical to the non-normalized data shown in Figure 34.4.

Figure 34.6. A pivot table created from normalized data.

34.2. Creating a Pivot Table

In this section, I describe the basic steps required to create a pivot table, using the bank account data described earlier in this chapter. Creating a pivot table is an interactive process. It's not at all uncommon to experiment with various layouts until you find one that you're satisfied with. If you're unfamiliar with the elements of a pivot table, see the upcoming sidebar, "Pivot Table Terminology."

34.2.1. Specifying the data

If your data is in a worksheet range, select any cell in that range and then choose Insert Tables PivotTable, which displays the dialog box shown in Figure 34.7.

Excel attempts to guess the range, based on the location of the active cell. If you're creating a pivot table from an external data source, you need to select that option and then click Choose Connection to specify the data source.

If you're creating a pivot table from data in a worksheet, it's a good idea to first create a table for the range (choose Insert Tables Table). Then, if you expand the table by adding new rows of data, Excel will refresh the pivot table without the need to manually indicate the new data range.

Figure 34.7. In the Create PivotTable dialog box, you tell Excel where the data is and where you want the pivot table.

34.2.2. Specifying the location for the pivot table

Use the bottom section of the Create PivotTable dialog box to indicate the location for your pivot table. The default location is on a new worksheet, but you can specify any range on any worksheet, including the worksheet that contains the data.

Click OK, and Excel creates an empty pivot table and displays its PivotTable Field List task pane, as shown in Figure 34.8.

Figure 34.8. Use the PivotTable Field List to build the pivot table.

The PivotTable Field List is typically docked on the right side of the Excel window. Drag its title bar to move it anywhere you like. Also, if you click a cell outside the pivot table, the PivotTable Field List is hidden.

34.2.3. Laying out the pivot table

Next, set up the actual layout of the pivot table. You can do so by using either of any techniques:

• Drag the field names (at the top) to one of the four boxes at the bottom of the PivotTable Field List.

• Place a check mark next to the item at the top of the PivotTable Field List. Excel will place the field into one of the four boxes at the bottom.

• Right-click a field name at the top of the PivotTable Field List and choose its location from the shortcut menu.

The following steps create the pivot table presented earlier in this chapter (see "A pivot table example"). For this example, I drag the items from the top of the PivotTable Field List to the areas in the bottom of the PivotTable Field List.

Figure 34.9. After a few simple steps, the pivot table shows a summary of the data.

34.2.4. Formatting the pivot table

Notice that the pivot table uses General number formatting. To change the number format for all data, right-click any value and choose Number Format from the shortcut menu. Then use the Format Cells dialog box to change the number format for the displayed data.

You can apply any of several built-in styles to a pivot table. Select any cell in the pivot table and then choose PivotTable Tools Design PivotTable Styles to select a style.

You also can use the controls from the PivotTable Design Layout group to control various elements in the pivot table. For example, you can choose to hide the grand totals if you prefer.

The PivotTable Tools Options Show group contains additional options that affect the appearance of your pivot table. For example, you use the Show Field Headers button to toggle the display of the field headings.

Still more pivot table options are available from the PivotTable Options dialog box, shown in Figure 34.10. To display this dialog box, choose PivotTable Tools Options PivotTable Options. Or, right-click any cell in the pivot table and choose Table Options from the shortcut menu.

Pivot Table Terminology Understanding the terminology associated with pivot tables is the first step in mastering this feature. Refer to the accompanying figure to get your bearings. Column labels: A field that has a column orientation in the pivot table. Each item in the field occupies a column. In the figure, Customer represents a column field that contains two items (Existing and New). You can have nested column fields. Grand totals: A row or column that displays totals for all cells in a row or column in a pivot table. You can specify that grand totals be calculated for rows, columns, or both (or neither). The pivot table in the figure shows grand totals for both rows and columns. Group: A collection of items treated as a single item. You can group items manually or automatically (group dates into months, for example). The pivot table in the figure does not have any defined groups. Item: An element in a field that appears as a row or column header in a pivot table. In the figure, Existing and New are items for the Customer field. The Branch field has three items: Central, North County, and Westside. AcctType has four items: CD, Checking, IRA, and Savings. Refresh: Recalculates the pivot table after making changes to the source data. Row labels: A field that has a row orientation in the pivot table. Each item in the field occupies a row. You can have nested row fields. In the figure, Branch and AcctType both represent row fields. Source data: The data used to create a pivot table. It can reside in a worksheet or an external database. Subtotals: A row or column that displays subtotals for detail cells in a row or column in a pivot table. The pivot table in the figure displays subtotals for each branch. Table Filter: A field that has a page orientation in the pivot table — similar to a slice of a three-dimensional cube. You can display only one item (or all items) in a page field at one time. In the figure, OpenedBy represents a page field that displays All (that is, not filtered). In previous version of Excel, a table filter was known as a Page field. Values area: The cells in a pivot table that contain the summary data. Excel offers several ways to summarize the data (sum, average, count, and so on).

Figure 34.10. The PivotTable Options dialog box.

34.2.5. Modifying the pivot table

After you create a pivot table, changing it is easy. For example, you can add further summary information by using the PivotTable Field List. Figure 34.11 shows the pivot table after I dragged a second field (OpenedBy) to the Row Labels section in the PivotTable Field List.

Figure 34.11. Two fields are used for row labels.

The following are some tips on other pivot table modifications you can make:

• To remove a field from the pivot table, select it in the bottom part of the PivotTable Field List and then drag it away.

• If an area has more than one field, you can change the order in which the fields are listed by dragging the field names. Doing so affects the appearance of the pivot table.

• To temporarily remove a field from the pivot table, remove the check mark from the field name in the top part of the PivotTable Field List. The pivot table is redisplayed without that field. Place the check mark back on the field name, and it appears in its previous section.

• If you add a field to the Report Filter section, the field items appear in a drop-down list, which allows you to filter the displayed data by one or more items. Figure 34.12 shows an example. I dragged the Date field to the Report Filter area. The report is now showing the data only for a single day (which I selected from the drop-down list in cell B1).

Pivot Table Calculations Pivot table data is most frequently summarized using a sum. However, you can display your data using a number of different summary techniques. Select any cell in the Values area of your pivot table and then choose PivotTable Tools Options Active Field Field Settings to display the Value Field Settings dialog box. This dialog box has two tabs: Summarize Values By and Show Values As. Use the Summarize Values By tab to select a different summary function. Your choices are Sum, Count, Average, Max, Min, Product, Count Numbers, StdDev, StdDevp, Var, and Varp. To display your values in a different form, use the drop-down control on the Show Values As tab. You have many options to choose from, including as a percentage of the total or subtotal.

Figure 34.12. The pivot table is filtered by date.

34.3. More Pivot Table Examples

To demonstrate the flexibility of this feature, I created some additional pivot tables. The examples use the bank account data and answer the questions posed earlier in this chapter (see "A pivot table example").

34.3.1. Question 1

What is the daily total new deposit amount for each branch?

Figure 34.13 shows the pivot table that answers this question.

• The Branch field is in the Column Labels section.

• The Date field is in the Row Labels section.

• The Amount field is in the Values section and is summarized by Sum.

Note that the pivot table can also be sorted by any column. For example, you can sort the Grand Total column in descending order to find out which day of the month had the largest amount of new funds. To sort, just right-click any cell in the column to sort and choose Sort from the shortcut menu.

Figure 34.13. This pivot table shows daily totals for each branch.

34.3.2. Question 2

Which day of the week accounts for the most deposits?

Figure 34.14 shows the pivot table that answers this question.

• The Weekday field is in the Row Labels section.

• The Amount field is in the Values section and is summarized by Sum.

I added conditional formatting data bars to make it easier to see how the days compare.

Figure 34.14. This pivot table shows totals by day of the week.

34.3.3. Question 3

How many accounts were opened at each branch, broken down by account type?

Figure 34.15 shows a pivot table that answers this question.

• The AcctType field is in the Column Labels section.

• The Branch field is in the Row Labels section.

• The Amount field is in the Values section and is summarized by Count.

The most common summary function used in pivot tables is Sum. In this case, I changed the summary function to Count. To change the summary function to Count, right-click any cell in the Value area and choose Summarize Data By Count from the shortcut menu.

Figure 34.15. This pivot table uses the Count function to summarize the data.

34.3.4. Question 4

What's the dollar distribution of the different account types?

Figure 34.16 shows a pivot table that answers this question. For example, 253 of the new accounts were for an amount of $5,000 or less.

Figure 34.16. This pivot table counts the number of accounts that fall into each value range.

This pivot table is unusual because it uses only one field: Amount.

• The Amount field is in the Row Labels section (grouped).

• The Amount field is also in the Values section and is summarized by Count.

• A third instance of the Amount field is the Values section, summarized by Percent of Total.

When I initially added the Amount field to the Row Labels section, the pivot table showed a row for each unique dollar amount. I right-clicked one of the Row Labels and chose Group from the shortcut menu. Then I used the Grouping dialog box to set up bins of $5,000 increments.

The second instance of the Amount field (in the Values section) is summarized by Count. I right-clicked a value and chose Summarize Data By Count from the shortcut menu.

I added another instance of Amount to the Values section, and I set it up to display the percentage. I right-clicked a value in column C and chose Show Values As % of Grand Total. This option is also available in the Show Values As tab of the Value Field Settings dialog box.

34.3.5. Question 5

What types of accounts do tellers open most often?

Figure 34.17 shows that the most common account opened by tellers is a Checking account.

• The AcctType field is in the Row Labels section.

• The OpenedBy field is in the Report Filters section.

• The Amount field is in the Values section (summarized by Count).

• A second instance of the Amount field is in the Values section (summarized by % of Total).

This pivot table uses the OpenedBy field as a Report Filter and is showing the data only for Tellers. I sorted the data so that the largest value is at the top, and I also used conditional formatting to display data bars for the percentages.

Figure 34.17. This pivot table uses a Report Filter to show only the Teller data.

34.3.6. Question 6

How does the Central branch compare with the other two branches?

Figure 34.18 shows a pivot table that sheds some light on this rather vague question. It simply shows how the Central branch compares with the other two branches combined.

• The AcctType field is in the Row Labels section.

• The Branch field is in the Column Labels section.

• The Amount field is in the Values section.

I grouped the North County and Westside branches together and named the group Other. The pivot table shows the amount, by account type. I also created a pivot chart for good measure. See Chapter 35 for more information about pivot charts.

Figure 34.18. This pivot table (and pivot chart) compares the Central branch with the other two branches combined.

34.3.7. Question 7

In which branch do tellers open the most checking accounts for new customers?

Figure 34.19 shows a pivot table that answers this question. At the Central branch, tellers opened 23 checking accounts for new customers.

• The Customer field is in the Report Filters section.

• The OpenedBy field is in the Report Filters section.

• The AcctType field is in the Report Filters section.

• The Branch field is in the Row Labels section.

• The Amount field is in the Values section, summarized by Count.

This pivot table uses three Report Filters. The Customer field is filtered to show only New, the OpenedBy field is filtered to show only Teller, and the AcctType field is filtered to show only Checking.

Figure 34.19. This pivot table uses three Report Filters.

34.4. Learning More

The examples in this chapter should give you an appreciation for the power and flexibility of Excel pivot tables. The next chapter digs a bit deeper and covers some advanced features — with lots of examples.