This skill covers writing SQL inside ADVPL/TLPP using blocks and their special macro expressions -- for physical table resolution, for branch filtering, for logical-deletion filtering, for safe variable binding, and for primary-key ordering. It also covers type declarations, JOIN and aggregation patterns, subqueries, and migrating legacy string-concatenation code to Embedded SQL.

Activate this skill whenever the user is writing a new query, reviewing an existing one for correctness/safety, or converting old concatenated-string SQL to the modern BeginSQL syntax. It also covers the restrictions and gotchas of BeginSQL (no at line start, always include and filial filtering, use , close aliases) and when to use instead for INSERT/UPDATE/DELETE.

It does not cover general native function lookups unrelated to SQL (see ), business-process context for which tables/fields to query (see ), or generating documentation for a routine that happens to contain SQL (see ).