EdgeDB schemas are declared using SDL (EdgeDB’s Schema Definition Language).
Your schema is defined inside .esdl files. Its common to define your
entire schema in a single file called default.esdl, but you can split it
across multiple files if you wish.
By convention, your schema
files should live in a directory called dbschema in the root of your
project.
# dbschema/default.esdl
type Movie {
required property title -> str;
required link director -> Person;
}
type Person {
required property name -> str;
}Syntax highlighter packages/extensions for .esdl files are available for
Visual Studio Code,
Sublime Text,
Atom, and Vim.
EdgeDB’s baked-in migration system lets you painlessly evolve your schema over
time. Just update the contents of your .esdl file(s) and use the EdgeDB CLI
to create and apply migrations.
$
edgedb migration createCreated dbschema/migrations/00001.esdl
$
edgedb migrateApplied dbschema/migrations/00001.esdl.
For a full guide on migrations, refer to the Creating and applying migrations guide.
A migration consists of a sequence of imperative schema-modifying commands
like create type, alter property, etc. Collectively these commands
are known as DDL (data definition language). We
recommend using SDL and the migration system when building applications,
however you’re free to use DDL directly if you prefer.
An EdgeDB instance is a collection of databases that store their data in a shared directory, listen for queries on a particular port, and are managed by a running EdgeDB process. Instances can be created, started, stopped, and destroyed locally with the EdgeDB CLI.
Each instance can contain several databases, each with a unique name. At
the time of creation, all instances contain a single default database called
edgedb. All incoming queries are executed
against it unless otherwise specified.
Each database has a schema consisting of several modules, each with a
unique name. Modules can be used to organize large schemas into logical units.
In practice, though, most users put their entire schema inside a single module
called default.
module default {
# declare types here
}Name resolution
When referencing schema objects from another module, you must use
a fully-qualified name in the form module_name::object_name.
The following module names are reserved by EdgeDB and contain pre-defined types, utility functions, and operators.
std: standard types, functions, and operators in the standard
library
math: algebraic and statistical functions
cal: local (non-timezone-aware) and relative date/time types and
functions
schema: types describing the introspection
schema
sys: system-wide entities, such as user roles and
databases
cfg: configuration and settings
