user: Question: What ordered has Helena as the name?
Columns: ['Name', 'Built by HM Dockyard', 'Ordered', 'Laid down', 'Launched']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Leveret (2nd of name)', 'Portsmouth', '25 March 1823', 'May 1823', '19 February 1825']
SQL:

assistant: SELECT "Ordered" FROM "Table" WHERE "Name" = 'Helena';