Creating A Free-Input Email Filter

A dashboard filter that allows users to paste in an email address requires special consideration. In particular, as mentioned on our filter documentation, special characters except hyphens and decimals are stripped out. In this post, we'll work around that to have a filter that works as shown below:

The filter itself

Using the filter in a query

To make this filter possible, we need to evaluate our column data as if it too has had the special characters stripped out. Typically, the special characters in an email address will be the at sign (@)and the period (.).

We'll do this using a matching expression & allowing free input. The setup should match the image below:

The code in the expression is as follows:

The code relies on the REPLACE function, which is available in most databases, including Redshift, Postgres, MySQL, and Snowflake.