Cross-database joins in Tableau - Dashboard Guide

Dashboard Mode - Cross-database joins

Business Question

How can we combine sales data from our SQL database with customer info from an Excel file to analyze total sales by customer region?

Sample Data

SQL Sales Data

OrderID	CustomerID	SalesAmount
1001	C001	250
1002	C002	450
1003	C003	300
1004	C001	150
1005	C004	500

Excel Customer Data

CustomerID	CustomerName	Region
C001	Alpha Corp	East
C002	Beta LLC	West
C003	Gamma Inc	East
C004	Delta Co	South
C005	Epsilon Ltd	North

Dashboard Components

• KPI Card: Total Sales - SUM([SalesAmount]) from joined data = 1650
• Bar Chart: Sales by Region - SUM([SalesAmount]) grouped by [Region]
• Table: Sales Details - Shows OrderID, CustomerName, Region, SalesAmount from joined data

Join Details: Inner join on CustomerID between SQL Sales Data and Excel Customer Data

Calculated Field for Sales by Region: SUM([SalesAmount])

Dashboard Layout

+----------------------+-----------------------+
|      Total Sales      |    Sales by Region    |
|       (KPI Card)      |      (Bar Chart)      |
+----------------------+-----------------------+
|                  Sales Details Table               |
+----------------------------------------------------+
  

Interactivity

A filter on Region lets users select one or more regions.

When a region is selected, the Sales by Region bar chart updates to show only those regions.

The Total Sales KPI updates to sum sales only for the selected regions.

The Sales Details table filters to show only orders from customers in the selected regions.

Self Check

If you add a filter for Region = East, which components update and what data do they show?

• Total Sales: Updates to 700 (250 + 300 + 150 from customers in East)
• Sales by Region: Shows only the East region bar with total 700
• Sales Details Table: Shows orders 1001, 1003, 1004 with customer names Alpha Corp and Gamma Inc

Key Result

Dashboard combining sales from SQL and customer regions from Excel to analyze total sales by region.