Someone recently asked me which queries are ad hoc in SQL Server. An ad hoc query is a single query not included in a stored procedure and not parameterized or prepared. Depending on the server settings, SQL Server can parameterize some statements initially written as ad hoc queries. Ad hoc doesn’t mean dynamic.
Next on the list, a post hoc ergo propter hoc query. That’s where I explain to the DBAs that just because the server goes down every time I run a query, it doesn’t mean my queries caused this.