This is a CLI tool that can introspect MySQL or Postgres databases and generate a Python source file that contains TypedDict definitions for the tables and columns in the provided database schema.
[!IMPORTANT] This tool generates Python source code that requires Python >=
3.10by default.
[!NOTE] You can use the
--minimum-python-version(-p) flag to change this. See the help documentation below for further clarification.
The intention of this tool is to help make it easier to write type-safe python code that interacts with databases.
If you have some example Python code that looks like this:
```python import psycopg2
with psycopg2.connect("dbname=testing user=postgres password=password") as conn: with conn.cursor() as cur: cur.execute("SELECT * FROM users") for row in cur.fetchall(): print(row) ```
If you assume for a moment that the users table has the following schema:
sql
CREATE TABLE users(
id SERIAL PRIMARY KEY,
name VARCHAR(255) NOT NULL,
email VARCHAR(255) NOT NULL,
created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
);
This tool can generate a Python file that looks like this:
```python import datetime from typing import TypedDict
class Users(TypedDict): id: int name: str email: str created_at: datetime.datetime ```
So that you can improve your code to look like this:
```python import psycopg2 from my_types import Users
with psycopg2.connect("dbname=testing user=postgres password=password") as conn: with conn.cursor() as cur: cur.execute("SELECT * FROM users") users: List[Users] = cur.fetchall() for row in users: print(user) # type-hinting is now available on this dict! ```
Note: It's a prerequisite that you have cargo installed. If you don't, you can install it here.
bash
cargo install db-introspector-gadget
bash
db-introspector-gadget -c mysql://root:password@127.0.0.1:3306/testing -s testing
bash
db-introspector-gadget -c postgres://postgres:password@localhost:5432/testing -s public
bash
db-introspector-gadget -c postgres://postgres:password@localhost:5432/testing -s public -o my_types.py
bash
db-introspector-gadget --help
or
bash
db-introspector-gadget -h
Which should output:
```bash A MySql and Postgres database introspection tool that generates Python types
Usage: db-introspector-gadget [OPTIONS] --connection-string
Options:
-c, --connection-string mysql://___ or postgres://___ of the database that you would like to introspect
-s, --schema