---
name: Query Writing
slug: query-writing
category: Data
description: Query Writing writes and executes SQL SELECT queries for single-table lookups, joins, aggregations, and reports. Use it when you need to retrieve or filter database data without modifying records.
github: "https://github.com/Idun-Group/idun-agent-platform/tree/main/examples/tutorials/text-to-sql-deep-agent/skills/query-writing"
language: Python
stars: 199
forks: 13
install: "npx degit https://github.com/Idun-Group/idun-agent-platform/tree/main/examples/tutorials/text-to-sql-deep-agent/skills/query-writing ~/.claude/skills/query-writing"
installs_to: ~/.claude/skills/query-writing
source_path: examples/tutorials/text-to-sql-deep-agent/skills/query-writing/SKILL.md
collection_size: 2
category_size: 762
collection_url: "https://dirskills.com/collections/Idun-Group/idun-agent-platform"
added: 2026-09-05T05:31:06.321Z
last_synced: 2026-09-05T05:31:06.321Z
canonical_url: "https://dirskills.com/skills/query-writing"
---

# Query Writing

Query Writing writes and executes SQL SELECT queries for single-table lookups, joins, aggregations, and reports. Use it when you need to retrieve or filter database data without modifying records.

**Install:**

```bash
npx degit https://github.com/Idun-Group/idun-agent-platform/tree/main/examples/tutorials/text-to-sql-deep-agent/skills/query-writing ~/.claude/skills/query-writing
```

## README

# Query Writing Skill

## Workflow for Simple Queries

For straightforward questions about a single table:

1. **Identify the table** - Which table has the data?
2. **Get the schema** - Use `sql_db_schema` to see columns
3. **Write the query** - SELECT relevant columns with WHERE/LIMIT/ORDER BY
4. **Execute** - Run with `sql_db_query`
5. **Format answer** - Present results clearly

## Workflow for Complex Queries

For questions requiring multiple tables:

### 1. Plan Your Approach
**Use `write_todos` to break down the task:**
- Identify all tables needed
- Map relationships (foreign keys)
- Plan JOIN structure
- Determine aggregations

### 2. Examine Schemas
Use `sql_db_schema` for EACH table to find join columns and needed fields.

### 3. Construct Query
- SELECT - Columns and aggregates
- FROM/JOIN - Connect tables on FK = PK
- WHERE - Filters before aggregation
- GROUP BY - All non-aggregate columns
- ORDER BY - Sort meaningfully
- LIMIT - Default 5 rows

### 4. Validate and Execute
Check all JOINs have conditions, GROUP BY is correct, then run query.

## Example: Revenue by Country
```sql
SELECT
    c.Country,
    ROUND(SUM(i.Total), 2) as TotalRevenue
FROM Invoice i
INNER JOIN Customer c ON i.CustomerId = c.CustomerId
GROUP BY c.Country
ORDER BY TotalRevenue DESC
LIMIT 5;
```

## Error Recovery

If a query fails or returns unexpected results:
1. **Empty results** — Verify column names and WHERE conditions against the schema; check for case sensitivity or NULL values
2. **Syntax error** — Re-examine JOINs, GROUP BY completeness, and alias references
3. **Timeout** — Add stricter WHERE filters or LIMIT to reduce result set, then refine

## Quality Guidelines

- Query only relevant columns (not SELECT *)
- Always apply LIMIT (5 default)
- Use table aliases for clarity
- For complex queries: use write_todos to plan
- Never use DML statements (INSERT, UPDATE, DELETE, DROP)