Data model

The DataModel is the paradigm-neutral schema produced by a scan. It is the aggregate of every Entity discovered, with relationships in both directions attached.

Entity

Each table or collection becomes an Entity:

interface Entity {
  namespace: string;            // schema (Postgres) or database (MySQL)
  name: string;                 // table name
  fields: readonly Field[];     // columns in declaration order
  identifier: readonly string[]; // primary key columns
  relationships: readonly Relationship[];
  constraints: readonly Constraint[];
  indexes: readonly Index[];
  description: string | null;   // table comment
}

Field

Each column becomes a Field with a normalized type category:

interface Field {
  name: string;
  type: FieldType;
  nullable: boolean;
  isIdentifier: boolean;
  defaultValue: string | null;
  description: string | null;
}

interface FieldType {
  category: FieldTypeCategory;
  nativeType: string;       // original type from the database
  length?: number;
  precision?: number;
  scale?: number;
  enumValues?: readonly string[];
  elementType?: FieldType;  // for array types
}

Type categories

Category	Postgres types	MySQL types
string	text, varchar, char, citext	varchar, char, text, tinytext, mediumtext, longtext
integer	int2, int4, int8, serial	tinyint, smallint, mediumint, int, bigint
decimal	numeric, float4, float8, money	decimal, float, double
boolean	bool	tinyint(1)
date	date	date, year
timestamp	timestamp, timestamptz	datetime, timestamp
time	time, timetz	time
json	json, jsonb	json
uuid	uuid	--
binary	bytea	binary, varbinary, blob, bit
enum	custom enum types	enum, set
array	any[]	--
unknown	everything else	everything else

Constraints

interface Constraint {
  name: string;
  kind: 'unique' | 'check' | 'exclusion' | 'custom';
  fields: readonly string[];
  expression: string | null;
}

Indexes

interface Index {
  name: string;
  fields: readonly string[];
  unique: boolean;
  kind: 'btree' | 'hash' | 'gin' | 'gist' | 'brin' | 'spgist' | 'unknown';
  partial: boolean;        // Postgres only
  definition: string | null;
}