SQL query writing is a challenging task for novices, even after considerable training. Query writing is a programming task and a translation task where the writer must translate a user's request for information into code that conforms to the structure, constraints, and syntax of an SQL SELECT statement and that references specific tables and columns from a database. This paper investigates the impact of two instructional interventions on query errors under conditions of low and high query complexity. Data was collected from an experimental study of 63 undergraduate students nearing completion of a 15-week database course. Our analysis reveals specific areas of query writing where each of the interventions helped, and hindered, task performance. We discuss the implications of these findings for improving SQL training and for future research on SQL training effectiveness.