Imported from MMostafa-Hub/deep-analytics-agent (skills/sql-analytics/SKILL.md). Install upstream with npx skills add MMostafa-Hub/deep-analytics-agent --skill sql-analytics. Copyright stays with the author.

SQL Analytics Skill

Tool

query — executes a single read-only SQL SELECT. Always inspect the live schema first.

General patterns

Aggregation with grouping

SELECT <dimension>, SUM(<measure>) AS total
FROM <table>
JOIN <other> ON <join_condition>
WHERE <filters>
GROUP BY <dimension>
ORDER BY total DESC
LIMIT 20;

Time-series bucketing

SELECT DATE_TRUNC('month', <date_column>) AS period,
       SUM(<measure>) AS value
FROM <table>
WHERE <date_column> >= NOW() - INTERVAL '12 months'
GROUP BY 1
ORDER BY 1;

Joining multiple tables

SELECT a.<col>, b.<col>, c.<col>
FROM <table_a> a
JOIN <table_b> b ON a.id = b.a_id
LEFT JOIN <table_c> c ON b.id = c.b_id
WHERE <conditions>;

Rules

• Only SELECT — no INSERT/UPDATE/DELETE/DDL
• Qualify column names with table aliases when joining to avoid ambiguity
• Use LIMIT unless the user explicitly wants all rows
• For percentages: ROUND(100.0 * numerator / NULLIF(denominator, 0), 2)