Connect to a custom SQL queryĪfter connecting to your data, double-click the New Custom SQL option on the Data Source page.
See the Legacy Connection Alternatives document in Tableau Community for alternatives to using the legacy connection. NOTE: Beginning with Tableau 2020.2, legacy Excel and Text connections are no longer supported. To connect to Excel or text files using the legacy connection, connect to the file, and in the Open dialog box, click the Open drop-down menu, and then select Open with Legacy Connection. Though there are several common reasons why you might use custom SQL, you can use custom SQL to union your data across tables, recast fields to perform cross-database joins, restructure or reduce the size of your data for analysis, etc.įor Excel and text file data sources, this option is available only in workbooks that were created before Tableau Desktop 8.2 or when using Tableau Desktop on Windows with the legacy connection. However, using custom SQL can be useful when you know exactly the information you need and understand how to write SQL queries. Because databases have slightly different SQL syntax from each other, the custom SQL you use to connect to one database might be different from the custom SQL you might use to connect to another. To a specific query rather than the entire data set.
