A database server receives an incoming query and converts the query into its canonical form. The database server compares the canonical incoming query with stored template queries. If the incoming query matches one of the stored template queries, then the query is legitimate and the query is executed on the database. If the canonical incoming query does not match one of the stored template queries, then the database server determines whether the incoming query is malicious or anomalous. The database server identifies tokens in the incoming query that are not present in a similar template query. If the tokens have meaning in the language utilized to express the query, the database server declares the query malicious. Otherwise, the database server declares the query anomalous.