Metadata-Version: 2.4
Name: db-snooper
Version: 0.0.17
Summary: Generate compact, LLM-ready database context with schema profiles and per-column data summaries.
Author-email: Renat Iuldashev <renatyv@gmail.com>
License-Expression: MIT
License-File: LICENCE
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: Programming Language :: Python :: 3.12
Classifier: Programming Language :: Python :: 3.13
Requires-Python: >=3.10
Requires-Dist: duckdb-engine>=0.13
Requires-Dist: psycopg>=3.2
Requires-Dist: pymysql>=1.1
Requires-Dist: sqlalchemy>=2.0
Description-Content-Type: text/markdown

# DB Snooper

[![PyPI](https://img.shields.io/pypi/v/db-snooper.svg)](https://pypi.org/project/db-snooper/)
[![Python](https://img.shields.io/pypi/pyversions/db-snooper.svg)](https://pypi.org/project/db-snooper/)

**Agent skill: [`src/db_snooper/skills/SKILL.md`](src/db_snooper/skills/SKILL.md)**

**Spec: [`spec/main.md`](spec/main.md)**

DB Snooper generates compact, LLM-ready database context for SQL generation, query debugging, and schema exploration. Profiling alone drives state-of-the-art text-to-SQL accuracy ([Automatic Metadata Extraction for Text-to-SQL](https://arxiv.org/abs/2505.19988)). Supports SQLite, PostgreSQL, MySQL, MariaDB, and DuckDB. Requires Python ≥ 3.10.

It inspects an existing database and produces a SQL profile (`<database>/<schema>.sql`): DDL, row counts, sampled rows, and per-column summaries. Use `--per-table` for one `.sql` per table.

AI agents and text-to-SQL pipelines can read this context instead of guessing table meanings.

## Quick Start

Install with pip:
```bash
pip install db-snooper
```

Or run instantly with `uvx` (no install needed):
```bash
uvx db-snooper profile --db-type mysql --user user --password password --database db --schema sch --port 3306
```

This creates a profile at `db/sch.sql`.

## What The Outputs Contain

The profile `.sql` file contains:

- Metadata with db-snooper version, UTC generation timestamp, SQL dialect, database name, and schema.
- `CREATE TABLE` DDL, indexes, and constraints.
- Total row counts.
- Deterministic sampled rows for small tables.
- Latest and random sampled rows for larger tables.
- Per-column null, non-null, distinct, numeric range, median, top-value, and shape summaries for larger tables.
- Catalog-derived estimates for very large tables (or metrics that are skipped on medium-large tables) from each engine's internal statistics — PostgreSQL `pg_stats`, MySQL `COLUMN_STATISTICS` histograms, and MariaDB `mysql.column_stats` — emitted with a `≈`/`(catalog)` marker so they are distinguishable from exact values.
- Top-level key frequencies for JSON/JSONB columns and min/avg/max element counts for ARRAY columns (when row counts allow).
- Redacted values for sensitive column names containing `password`, `passwd`, `pwd`, `hash`, `salt`, `secret`, or `token`.
- A `-- skipped technical tables:` line naming migration/framework tables excluded from the profile.

## Database Examples

### SQLite
```bash
db-snooper profile --db-type sqlite --database path/to/app.sqlite
```

### PostgreSQL
Profile
```bash
db-snooper profile --db-type postgres --database app_db --schema sch --user readonly_user --host localhost --port 5432 --ask-password
```

### MySQL
```bash
db-snooper profile --db-type mysql --database app_db --user readonly_user --host localhost --port 3306 --ask-password
```

### MariaDB
```bash
db-snooper profile --db-type mariadb --database app_db --user readonly_user --host localhost --port 3306 --ask-password
```

### DuckDB
```bash
db-snooper profile --db-type duckdb --database warehouse.duckdb --schema sch
```

## Environment Variables

Connection values can come from environment variables instead of flags:

```bash
DB_SNOOPER_DB_TYPE=sqlite \
DB_SNOOPER_DATABASE=eval-dataset/student_club/student_club.sqlite \
db-snooper profile
```

Supported variables:

- `DB_SNOOPER_DB_TYPE`
- `DB_SNOOPER_DATABASE`
- `DB_SNOOPER_DB_HOST`
- `DB_SNOOPER_DB_PORT`
- `DB_SNOOPER_DB_USER`
- `DB_SNOOPER_DB_PASSWORD`
- `DB_SNOOPER_SCHEMA`

For server databases, `--host` defaults to `localhost`, `--port` defaults to the database default, and DB Snooper securely prompts for a password when `DB_SNOOPER_DB_PASSWORD` is not set.

## Help

```bash
db-snooper -h
db-snooper profile -h
```

Table filters:

```bash
db-snooper profile --db-type sqlite --database app.sqlite --include-tables users,orders,line_items
```

Schema filter:

```bash
db-snooper profile --db-type postgres --database app_db --schema reporting --user readonly_user --port 5432 --ask-password
DB_SNOOPER_SCHEMA=reporting db-snooper profile --db-type postgres --database app_db --user readonly_user --port 5432 --ask-password
```

Profile options:

- `--small-table-threshold 50`: tables with this many rows or fewer are sampled instead of column-profiled.
- `--large-table-threshold 100000000`: tables whose catalog row estimate is at/above this count are profiled from internal database stats only. `COUNT(*)`, sampled rows, and per-column queries are skipped because they would be too slow on hundreds of millions of rows. Instead, each column is summarized from the engine's catalog statistics (approximate null fraction, distinct count, numeric min/max, and top values), marked with `≈`/`(catalog)`.
- `--sample-row-limit 50`: maximum sampled rows for small tables.
- `--include-tables table_a,table_b`: only profile selected tables.
- `--exclude-tables table_c`: skip selected tables.
- `--include-technical-tables`: profile migration/framework tables (e.g. `schema_migrations`, `alembic_version`, `flyway_schema_history`, `django_migrations`) that are skipped by default.
- `--per-table`: generate one `.sql` profile for each table instead of a single schema profile.

## Python API

Use the simple helpers when you have a SQLAlchemy URL:

```python
from db_snooper import generate_profile

database_url = "sqlite:///eval-dataset/superhero/superhero.sqlite"

profile_sql = generate_profile(database_url)
```

Use the lower-level API when you already have a SQLAlchemy engine or need options:

```python
from sqlalchemy import create_engine
from db_snooper import ProfileOptions, profile_database

engine = create_engine("sqlite:///eval-dataset/superhero/superhero.sqlite")

profile_sql = profile_database(
    engine,
    ProfileOptions(sample_row_limit=25, include_tables=frozenset({"superhero", "publisher"})),
)
```

## Agent Skill

DB Snooper bundles [`db-snooper-profile`](src/db_snooper/skills/SKILL.md), an [agent skill](https://opencode.ai/docs/skills/) for generating schema and data context before writing or debugging SQL. It runs `db-snooper profile` and produces `<database>/<schema>.sql`.

Install it as a Claude Code plugin:

```text
/plugin marketplace add renatyv/db-snooper
/plugin install db-snooper@db-snooper
```

The skill ships inside the wheel, so you can inspect or install it without cloning this repository:

```bash
uvx db-snooper skills list
uvx db-snooper skills install
uvx db-snooper skills install --target all
uvx db-snooper skills install --dir ./.opencode/skills --force
```

By default, installation targets `~/.config/opencode/skills`. Use `--target` for Claude or agents-compatible directories, or `--dir` for a custom location.

## License

The DB Snooper source code is licensed under the MIT License. See `LICENCE`.

Third-party Python dependencies remain under their own upstream licenses. See `THIRD_PARTY_NOTICES.md` for a dependency license summary.

The dataset files included under `eval-dataset/` are derived from [birdsql](https://bird-bench.github.io/) by The BIRD Team, and are used and redistributed under the [Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0)](https://creativecommons.org/licenses/by-sa/4.0/).

These files are not covered by the MIT source-code license. They retain their original CC BY-SA 4.0 terms. Any derivative works that include these files must also be distributed under CC BY-SA 4.0.
