<invoke name="query_sql"> <parameter name="sql">SELECT COUNT(*) AS n_rows, COUNT(DISTINCT Student_ID) AS distinct_ids, COUNT(*) - COUNT(Perceived_Stress_Score) AS stress_nulls, COUNT(*) - COUNT(Academic_Performance_GPA) AS gpa_nulls, MIN(Age) AS min_age, MAX(Age) AS max_age, SUM(CASE WHEN Academic_Level = 'High School' AND Age >= 19 THEN 1 ELSE 0 END) AS hs_aged_19_plus, SUM(CASE WHEN Daily_Usage_Hours + Sleep_Duration_Hours > 20 THEN 1 ELSE 0 END) AS time_budget_over_20, MIN(Daily_Usage_Hours) AS min_usage, MAX(Daily_Usage_Hours) AS max_usage, MIN(Sleep_Duration_Hours) AS min_sleep, MAX(Sleep_Duration_Hours) AS max_sleep, MIN(Perceived_Stress_Score) AS min_stress, MAX(Perceived_Stress_Score) AS max_stress, MIN(Mental_Health_Index) AS min_mh, MAX(Mental_Health_Index) AS max_mh, MIN(Academic_Performance_GPA) AS min_gpa, MAX(Academic_Performance_GPA) AS max_gpa FROM raw.Social_media_impact_on_life</parameter> <parameter name="purpose">Re-verify the key data-quality figures (keys, nulls, ranges, age/level mismatch) before giving the final answer</parameter> <parameter name="source">raw</parameter> </invoke>