With appropriate configuration, TOPCAT can write out tables as new tables in an SQL-compatible relational database. For this to work, you must have write access to a suitable database and the drivers must be installed as described in the section about reading from SQL databases.
For writing, the location is specified as the following URL:
jdbc:<driver-specific-url>#<new-table-name>Here is an example for MySQL:
jdbc:mysql://localhost/astro1?user=mbt#newtabwhich would write the current contents of the browser into a new table called "newtab" in the database "astro1" on the local host with the access privileges of user mbt.
Fortunately you do not have to construct this URL by hand, there is a dialogue to assist in putting it together. You can use this by pressing the "SQL Database" button in the "Save Table" dialogue. This includes optional username and password inputs for establishing the connection with the database. If you do not specify them and the database server rejects the connection you will be prompted for these separately.
TOPCAT has so far only been tested with the MySQL database and its Connector/J JDBC driver. Other databases and drivers may or may not work.