I'm using tableau Desktop V9.1.13 with two tables from different data sources (one comes from Bigquery and the other from a postgresql DB) and I want to perform a multiplication between two columns of these tables. The first table has one row for a single transaction and the other has one row for each currency available in the database. I've tried blending and create a calculated field but the last always throws an error. The first table looks like this:
+----------------+--------+----------+
| transaction-id | Value | Currency |
+----------------+--------+----------+
| 123-abc | 120 | BRL |
+----------------+--------+----------+
| 556-fds | 100 | PEN |
+----------------+--------+----------+
| 456-cde | 120000 | COP |
+----------------+--------+----------+
| 789-fgr | 100 | MXN |
+----------------+--------+----------+
And the other table
+----------+--------------+
| Currency | Value in USD |
+----------+--------------+
| COP | 0.0003 |
+----------+--------------+
| BRL | 0.3169 |
+----------+--------------+
| PEN | 0.2958 |
+----------+--------------+
| MXN | 0.0539 |
+----------+--------------+
Now I want to generate a new column called Value_USD that is the product of the transaction amount with the value of its currency.
+----------------+--------+----------+-----------+
| transaction-id | Value | Currency | Value_USD |
+----------------+--------+----------+-----------+
| 123-abc | 120 | BRL | 38 |
+----------------+--------+----------+-----------+
| 556-fds | 100 | PEN | 29.58|
+----------------+--------+----------+-----------+
| 456-cde | 120000 | COP | 40 |
+----------------+--------+----------+-----------+
| 789-fgr | 100 | MXN | 5.39 |
+----------------+--------+----------+-----------+