In Solution Explorer, right-click Cubes, and then click New Cube. On the Select Creation Method page of the Cube Wizard, select Use existing tables, and then click Next. You might occasionally have to create a cube without using existing tables. To create an empty cube, select Create an empty cube.

To generate multiple grouping sets using the SQL Server CUBE operator, you can follow these steps:

1. Start by writing a SELECT statement that includes the columns you want to retrieve data from and the table or tables you want to query.
2. Specify the CUBE operator in the GROUP BY clause of your SELECT statement. The CUBE operator generates all possible combinations of grouping sets for the specified columns.

   For example, if you have three columns A, B, and C, the CUBE operator will generate grouping sets for (A, B, C), (A, B), (A, C), (B, C), (A), (B), (C), and an empty set.

   Here’s an example of a SELECT statement using the CUBE operator:

   <span class="hljs-keyword">SELECT</span> A, B, C, <span class="hljs-built_in">SUM</span>(D) <span class="hljs-keyword">AS</span> Total
<span class="hljs-keyword">FROM</span> YourTable
<span class="hljs-keyword">GROUP</span> <span class="hljs-keyword">BY</span> <span class="hljs-keyword">CUBE</span> (A, B, C)


3. Execute the SELECT statement, and SQL Server will return the result set with all the generated grouping sets.

   The result set will include rows with aggregated data for each grouping set, along with the corresponding NULL values for the columns that are not included in that particular grouping set.

   For example, if the table has the following data:

   <span class="hljs-selector-tag">A</span> | <span class="hljs-selector-tag">B</span> | C | D
--|---|---|--
<span class="hljs-number">1</span> | <span class="hljs-number">2</span> | <span class="hljs-number">3</span> | <span class="hljs-number">10</span>
<span class="hljs-number">1</span> | <span class="hljs-number">2</span> | <span class="hljs-number">4</span> | <span class="hljs-number">20</span>


   The result set using the CUBE operator will be:

   <span class="hljs-selector-tag">A</span> | <span class="hljs-selector-tag">B</span> | C | Total
--|---|---|------
<span class="hljs-number">1</span> | <span class="hljs-number">2</span> | <span class="hljs-number">3</span> | <span class="hljs-number">10</span>
<span class="hljs-number">1</span> | <span class="hljs-number">2</span> | | <span class="hljs-number">30</span>
<span class="hljs-number">1</span> | | <span class="hljs-number">3</span> | <span class="hljs-number">10</span>
<span class="hljs-number">1</span> | | | <span class="hljs-number">30</span>
| <span class="hljs-number">2</span> | <span class="hljs-number">3</span> | <span class="hljs-number">10</span>
| <span class="hljs-number">2</span> | | <span class="hljs-number">30</span>
| | <span class="hljs-number">3</span> | <span class="hljs-number">10</span>
| | | <span class="hljs-number">30</span>


   The Total column represents the sum of column D for each grouping set.

That’s it! You can use the CUBE operator to generate multiple grouping sets in SQL Server. The result set will contain aggregated data for each grouping set, including combinations of columns specified in the CUBE operator.