export interface ColumnInfo {
    name: string;
    /** Raw SQL/DB type string, e.g. 'INTEGER', 'TEXT', 'boolean', 'timestamp without time zone' */
    type: string;
    notNull: boolean;
    pk: boolean;
    defaultValue: string | null;
    /** True for virtual or stored generated columns — these are read-only and never inserted. */
    generated?: boolean;
    /**
     * Underlying DB type name (Postgres `udt_name`). For an enum column `type` is
     * the generic `'USER-DEFINED'`, while `udtName` holds the actual enum type
     * name used to resolve its values. Undefined on SQLite (no native enums).
     */
    udtName?: string;
    /**
     * String-literal enum values for this column, when known. On SQLite (no native
     * enums) these come from a `CHECK (col IN ('a','b',…))` constraint — the CHECK
     * *is* the enum definition. Typed as a union, mirroring a Postgres enum column.
     */
    enumValues?: string[];
}
export interface ForeignKeyInfo {
    column: string;
    foreignTable: string;
    foreignColumn: string;
}
export interface EnumInfo {
    name: string;
    schema: string;
    values: string[];
}
export interface DbIntrospector {
    listTables(): Promise<string[]>;
    getColumns(table: string): Promise<ColumnInfo[]>;
    getForeignKeys(table: string): Promise<ForeignKeyInfo[]>;
    /**
     * Columns for every table in one sweep, keyed by the same table name that
     * {@link listTables} returns (schema-qualified for non-`public` tables). On
     * Postgres this is a single set-based query — introspecting a large schema
     * must not fan out one round-trip per table, which both scales O(tables) and
     * overlaps queries on a single connection.
     */
    getAllColumns(): Promise<Map<string, ColumnInfo[]>>;
    /**
     * Foreign keys for every table in one sweep, keyed like {@link getAllColumns}.
     * Tables with no foreign keys may be omitted from the map.
     */
    getAllForeignKeys(): Promise<Map<string, ForeignKeyInfo[]>>;
    listEnums(): Promise<EnumInfo[]>;
    close(): Promise<void>;
}