Simple DB schema for ChaiSQL¶

(backlog): Features supported in Python chai_sql

parser for the database format

evaluation

To support basic schema operations, we provide a simple syntax for describing DB relations.

Included features¶

This schema is purposefully simplified and allows to specify only the very basic information about the relations.

Only the checked features below are supported:

Example¶

Example schema definition in ChaiSQL schema syntax

types: { Number, String, Boolean }

relation Cat: {
    id: Number,
    name: String,
}

relation Person: {
    id: Number,
    name: String,
    age: Number,
}

Syntax¶

Below is the defintion of the abstract syntax of the schema file:

Approximate syntax definition for ChaiSQL schemas

-- Collection of declared type names
(
    types: { (<Type>,)* }
)?

-- Listing of all relations
(
    relation <Name>: { (<Key>: <Type>,)+ }
)*

Semantic correctness¶

The following properties should be respected for a schema to be semantically correct.

All custom defined types should be declared with types: [...]
Relation attribute types are be available in types: [...]
The types collection can only be declared once
The types collection contains no duplicate types
Relation names should be unique
Each relation should have at least one attribute
Attribute names within each relation should be unique