In Excel 2007, when you create a second pivot table from the same source data, you don't get an option to base the new pivot table on an existing pivot table, the way you can in Excel 2003.

In Step 1 of the Excel 2003 Wizard, you can select the first option, to create an independent pivot table. Or, select the fourth option, for pivot tables that share the same pivot cache.

In Excel 2007, if you create two pivot tables from the same source data, they automatically use the same pivot cache of the source data. You don't have an option to create an independent pivot table.

Grouping Problems

Because the pivot tables share the same cache, this can cause problems if you group the data in the pivot fields.

When you change the grouping in one pivot table, the same grouping appears in the other pivot table. For example, change the date grouping in the first pivot table to Months, and the dates in the second pivot table automatically group in Months.

Because you created the two pivot tables from the same source data, by default they use the same pivot cache, which is where the grouping is stored.

However, you might want different grouping in the two pivot tables. For example, you'd like Month grouping in one pivot table, and Quarter grouping in the other.

Create a Second Pivot Cache

To use different grouping in each pivot table, you'll need to create a separate pivot cache for each pivot table. Use the following easy method, suggested in the Excel newsgroups by Dave Peterson.

To create a separate pivot cache for the second pivot table:

1. Cut the second pivot table, and paste it into a new workbook.
2. Change the grouping of the second pivot table.
3. Cut the second pivot table from the new workbook, and paste it back into the original workbook.

Now there are two pivot caches in the original workbook, and each pivot table can be grouped independently.

Watch the Video

To see the steps for creating a second pivot cache so you can create separate grouping in the pivot tables, please watch this Excel video tutorial.

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In a pivot table, there's no built-in way to group the pivot table data by both weeks and months at the same time. If you want to show sales data by week, you can group the date field in seven-day intervals.

The 7 day grouping works well, but if you try to add grouping by months, the Number of Days option is disabled. If you select Month in the Grouping dialog box, the days will lose their 7 day grouping.

Calculate the Month

Since you can't group by both week and month, you can use a workaround instead. You could create a column in the source data, and then calculate one of the grouping levels there. Then, you could add that field to the pivot table.

For example, you can add a column that calculates the month name for each sales order date, by using the TEXT function:

=TEXT(A2,"mmm")

Add the Month field to the pivot table, above the weeks.

Calculate the Week Number

Another option is to add a column to the source data, with a formula to calculate the week number:

=WEEKNUM(A2).

With the OrderDate field in the Row Labels area, group the dates by months. In the Row Labels area, add the WeekNum field below the OrderDate field, to summarize the data by month and week number.

Note: If a week begins in one month and ends in another, it will appear under both months.

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You might have to make changes to a workbook that contains a pivot table. If someone else created that workbook, you may not be sure where to find the Excel table that was used as the pivot table's source data. In some workbooks there can be several Excel tables, and it's not immediately obvious which table was used.

How To Locate the Source Data

To locate the source data, follow these steps:

1. Select any cell in the pivot table.

2. On the Ribbon, under the PivotTable Tools tab, click the Options tab.

3. In the Data group, click the top section of the Change Data Source command.

In the Change PivotTable Data Source dialog box, you can see the the source table or range in the Table/Range box. This may be a worksheet reference, such as

• Sales_North!$A$1:$O$500

or a table name, such as

• Sales_East

On the worksheet, behind the dialog box, you can see the source range, surrounded by a moving border.

4. Click OK, to close the dialog box.

Unhide a Sheet

Usually the source range will be visible, and surrounded by a moving border. If the source range isn't activated, it may be on a hidden worksheet. You can follow these steps to unhide a sheet:

1. On the Ribbon, click the Home tab

2. In the Cells group, click Format.

2. In the Visibility section, click Hide & Unhide, and then click the Unhide Sheet command.

3. In the list, select the sheet that you want to make visible, and click OK.

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For more information on pivot tables, see the Pivot Table Topics on my Contextures web site.

In Excel 2007, you added a date field to the pivot table's Row area, and you want to group the dates by year. However, you get an error message, "Cannot group that selection", when you try to group the dates.

This error occurs if there are cells in the source data that contain text, instead of dates. For example, you may have entered text such as N/A, if a date was not available when the data was being entered.

To correct the problem, do the following:

1. In rows contain text, such as N/A, delete the text, and leave the cell blank, or replace the text with a date.
2. Refresh the pivot table, and try to group the dates.
3. If you’re still unable to group the dates, remove the date field from the pivot table layout, refresh the pivot table, then add the date field to the pivot table again.

Note: In earlier versions of Excel, blank cells will also cause this error message. You can fill in actual dates, or use dummy dates, such as 2/2/2099, in the source data. Do not leave the cells blank if you want to group the dates.

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For more information on pivot tables, see the Pivot Table Topics on my Contextures web site.