Sqlalchemy DB graphing tool version 0.2.0

A module to display sqlalchemy database tables and keys as a graph. Inspired by https://pypi.org/project/sqlalchemy-schemadisplay/.

license: MIT license

Features

Generate graphs from your sqlalchemy declarative database in one simple function call.

How to use:

from sqlalchemy_db_graphing import generate_graph_as_png
from mymodule.database_schema import MySQLAlchemySchema

filename = "path/to/save/file.png"
generate_graph_as_png(metadata=MySQLAlchemySchema.metadata, filename=filename)

generate_graph_as_png also supports arguments:

• style_options: either a string referring to a style preset, or a dictionary of options defining the style of each graphviz node. Keys are: - table_style: Style of each table (table element). - table_name_style: Style of the table name (font element). - header_style: Style of the table headers (td element). - schema_name_style: Style of the schema name (font element). - pk_style: Style of a column identified as a primary key (td element). - fk_style: Style of a column identified as a foreign key (td element). - pk_fk_style: Style of a column identified as both a primary and foreign key (td element). - column_style: Style of all other columns (td element). - legend_style: Style of the legend (table element).
• display_legend: whether the legend is displayed or not.

Style options dict example (Default style):

{
    "table_style": "cellborder='1' cellspacing='0' cellpadding='4' border='1' style='rounded'",
    "table_name_style": "color='red'",
    "header_style": "align='center' bgcolor='grey' border='0'",
    "schema_name_style": "color='black'",
    "pk_style": "align='left' bgcolor='#99CCFF' border='0'",
    "fk_style": "align='left' bgcolor='#CCFF99' border='0'",
    "pk_fk_style": "align='left' bgcolor='#99CCFF' border='0'",
    "column_style": "align='left' border='0'",
    "legend_style": "border='0' cellpadding='2' cellspacing='0'"
}

Finally, all graphviz keyword arguments are supported, see https://graphviz.org/docs/graph/ for a comprehensive list.

generate_graph_as_png(
        metadata=MySQLAlchemySchema.metadata,
        filename=filename,
        style_options="blue_rounded",
        display_legend=False,
        rankdir="LR",  # Draw the graph from Left to Right instead of Top Down.
        splines = "ortho",
)

generate_graph_as_png(
        metadata=MySQLAlchemySchema.metadata,
        filename=filename,
        style_options="purple_rounded",
        display_legend=False,
        rankdir="TD",
        splines = "curved",
)

generate_graph_as_png(
        metadata=MySQLAlchemySchema.metadata,
        filename=filename,
        style_options="purple_blue",
        display_legend=False,
        rankdir="TD",
        splines = "curved",
)

The module also includes a few other functions:

• generate_graph_as_svg for svg pictures generation.
• generate_graph_as_pydot to get a pydot representation of your declarative base.
• get_schema_metadata_from_live_database to retrieve the metadata from a live database instead of the declarative database

Example with live database:

from sqlalchemy_db_graphing import get_schema_metadata_from_live_database

database_url = f"postgresql+psycopg2://username:password@host:port/db_name"
metadata = get_schema_metadata_from_live_database(url=database_url, schema="my_app_schema")

Credits

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

• Cookiecutter: https://github.com/audreyr/cookiecutter
• audreyr/cookiecutter-pypackage: https://github.com/audreyr/cookiecutter-pypackage