apito-io / sqlreflect

Introspect a database, learning about its schema and relationships.

SQL Reflect

THIS IS HIGHLY EXPERIMENTAL AND UNDER ACTIVE DEVELOPMENT

This library provides access to the structure of a SQL database, allowing developers to "reflect" on the database itself. Why would you need to do this?

• Find out all of the tables available in a database
• For a table, find out what columns it has
• Find out about the relationships between tables
  • Discover foreign keys, and automatically relate tables
  • Discover primary keys

How It Works

This uses the information_schema database defined in the SQL standard. The library is developed against PostgreSQL, but it should work on any database that provides an approximately compliant implementation.

The information_schema tables (or views) provide information about the structure of a database, and are designed to enable this sort of reflection.

As the name of the library suggests, the code is designed to feel roughly similar to Go's own reflection package. However, there is not a one-to-one mapping between a concept like a table or column and Go's concepts like type and value.

Under the hood, it uses squirrel and structable 4.

Tested on:

• Postgres 9.4, 9.6

Terminology

For the most part, this library follows the terminology of the SQL standard (e.g. catalog usually means database). Because I am most familiar with PostgreSQL, it is likely that some Postgres terminology slipped in here too.

Most of my understanding of the information schema comes from the PostgreSQL documentation.

TODO

• Enable querying CHECK constraints to actually return the constraint. (See information_schame.check_constraints)