In addition to invoking Database mashables, you can issue individual SQL statements on datasources in a mashup script. You can send queries with the <sql> statement or issue any other SQL statement with <sqlUpdate>. EMML also includes statements to manage SQL transactions (see SQL Transactions). You can also invoke stored procedures directly with <sqlcall>.

Presto administrators must define data sources for the databases that you want to work with in the Admin Console.

In rare cases, you may also need to explicitly define datasources in mashup scripts. See Declaring Data Sources and Configuring Datasource Drivers for more information.