kddl

// Definition for database geo

// a database contains schemas
database geo {

  option id_suffix = '_key' // default is '_id'

  // a schema contains tables and links
  schema infra {

    // a table contains fields, either given a type or a destination table
    table zone {
      *code varchar(10)      // '*' stands for 'part of pk', otherwise pk is generated as needed
      name varchar(50)       // not null by default
      description text?      // '?' stands for nullable field
      active boolean = false // default value
    }

    table department : zone // inherit a table from another (for engines which support table inheritance like PostgresQL)

    table city : zone { hasTrain boolean? }  // declarations can be inlined

    table link {
      distance integer // types are : boolean, integer, long, float, double, time, date, datetz, datetime, datetimetz, varchar(*n*), text
      src_id --> zone    // mandatory foreign key field
      dst_id --> zone    // idem
      hub_id ..> zone (down)   // nullable foreign key field
    }

    city *--> department (up) // plantuml arrow direction can be specified
  }

  schema client {

    table contact {
      gender, lastname, firstname // field types are optional, use a coma to disambiguate
    }

    table location {
      name varchar(50) = 'untitled' // string literals use single quotes
      address text?
    }

    location *..> infra.zone // foreign key referencing a table in another schema

  }

}

kddl -i example.kddl -f plantuml > example.pu
plantuml -Tpng example.pu
eog example.png

kddl -i example.kddl -f postgresql > example.sql

git clone git@gitlab.renegat.net:claude/kddl.git
./install.sh

ln -s ~/<path_to_kddl_repository>/kddl.sh ~/bin/kddl