How to make duplicated rows to show only one row with a number to indicate the number of duplicated rows?

This often happens when we run query, there are multiple duplicated rows, e.g., for a material, the customer wants us to only show one row content, other rows with blank content and there is number to indicate how many duplicated rows.  The layout example is as following:

Customer 1       Material 1

                         Material 2

                         Material 2

                         Material 2

                         Material 3

Customer 2       Material 1

                         Material 1

                         Material 2

                         Material 3

We can see Material 2 for Customer 1 gets duplicated for 3 times and Material 1 gets duplicated for Customer 2 twice.  Now the customer wants to see the layout as following:

Customer 1       Material 1

                         Material 2       3

                         Material 3

Customer 2       Material 1     2

                         Material 2

                         Material 3

Anyway to get the above layout effect?

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Thanks!

Kevin