Class FeatureDao

Data Access Object for GeoPackage feature tables.

Extends UserDao with spatial query capabilities including bounding box queries (with R-tree index support), GeoJSON conversion, and geometry metadata access. This is the primary class for reading and writing spatial features in a GeoPackage.

Example

const featureDao = new FeatureDao(conn, featureTable, geometryColumns);

// Iterate over all features as GeoJSON
for (const feature of featureDao.queryForGeoJSON()) {
  console.log(feature.properties);
}

// Spatial query with bounding box
const bbox = { minX: -180, minY: -90, maxX: 180, maxY: 90 };
for (const feature of featureDao.queryForGeoJSONWithBoundingBox(bbox)) {
  console.log(feature.geometry);
}

Hierarchy (View Summary)

UserDao
- FeatureDao

Index

Constructors

constructor

new FeatureDao(
    conn: GeoPackageConnection,
    featureTable: FeatureTable,
    geometryColumns: GeometryColumns,
): FeatureDao
Creates a new FeatureDao instance.
Parameters
- conn: GeoPackageConnection
  The GeoPackage database connection.
- featureTable: FeatureTable
  The feature table definition including geometry column metadata.
- geometryColumns: GeometryColumns
  The geometry columns metadata from the gpkg_geometry_columns table.
Returns FeatureDao
Overrides UserDao.constructor
- Defined in src/features/feature-dao.ts:67

Properties

`Protected`conn

conn: GeoPackageConnection

The underlying database connection.

`Protected`table

table: UserTable

The user table schema that this DAO operates on.

Accessors

geometryColumnName

get geometryColumnName(): string
Gets the name of the geometry column in this feature table.

Returns string
The geometry column name (e.g., "geometry" or "geom").
- Defined in src/features/feature-dao.ts:78

geometryType

get geometryType(): string
Gets the geometry type name for this feature table.

Returns string
The geometry type as defined in the gpkg_geometry_columns table (e.g., "POINT", "LINESTRING", "POLYGON", "GEOMETRY").
- Defined in src/features/feature-dao.ts:88

tableName

get tableName(): string
Gets the name of the table managed by this DAO.

Returns string
The table name string.
Inherited from UserDao.tableName
- Defined in src/user/user-dao.ts:45

Methods

count

count(where?: string, ...params: unknown[]): number
Counts rows in the table, optionally filtered by a WHERE clause.
Parameters
- Optionalwhere: string
  An optional SQL WHERE clause (without the WHERE keyword).
- ...params: unknown[]
  Bind parameters for placeholders in the WHERE clause.
Returns number
The count of matching rows.
Example
```
const total = dao.count();
const active = dao.count('"status" = ?', 1);
```
Inherited from UserDao.count
- Defined in src/user/user-dao.ts:219

deleteById

deleteById(id: number): number
Deletes a single row by its primary key value.
Parameters
- id: number
  The primary key value of the row to delete.
Returns number
The number of rows deleted (0 or 1).
Example
```
const deleted = dao.deleteById(42);
console.log(deleted ? 'Row deleted' : 'Row not found');
```
Inherited from UserDao.deleteById
- Defined in src/user/user-dao.ts:202

deleteWhere

deleteWhere(where: string, ...params: unknown[]): number
Deletes rows matching a SQL WHERE clause.
Parameters
- where: string
  A SQL WHERE clause (without the WHERE keyword).
- ...params: unknown[]
  Bind parameters for placeholders in the WHERE clause.
Returns number
The number of rows deleted.
Example
```
const deleted = dao.deleteWhere('"status" = ?', 0);
console.log(`Deleted ${deleted} row(s)`);
```
Inherited from UserDao.deleteWhere
- Defined in src/user/user-dao.ts:185

getBoundingBox

getBoundingBox(): BoundingBox | null
Retrieves the bounding box for the entire feature table from the gpkg_contents metadata.

Returns BoundingBox | null
The BoundingBox of the table's spatial extent, or null if the bounding box is not defined in gpkg_contents.
Example
```
const bbox = featureDao.getBoundingBox();
if (bbox) {
  console.log(`Extent: [${bbox.minX}, ${bbox.minY}] to [${bbox.maxX}, ${bbox.maxY}]`);
}
```
- Defined in src/features/feature-dao.ts:225

getGeometryColumns

getGeometryColumns(): GeometryColumns
Returns the full geometry columns metadata record.

Returns GeometryColumns
The GeometryColumns object containing table name, column name, geometry type, SRS ID, and Z/M flags.
- Defined in src/features/feature-dao.ts:98

getSrsId

getSrsId(): number
Gets the Spatial Reference System ID for the geometry column.

Returns number
The SRS ID (e.g., 4326 for WGS 84).
- Defined in src/features/feature-dao.ts:107

getTable

getTable(): UserTable
Returns the full user table definition managed by this DAO.

Returns UserTable
The UserTable schema object.
Inherited from UserDao.getTable
- Defined in src/user/user-dao.ts:54

insert

insert(row: UserRow): number
Inserts a new row into the table.

The row's values are inserted into the corresponding columns. The primary key value from the row is typically omitted to allow AUTOINCREMENT to assign an ID automatically.
Parameters
- row: UserRow
  The UserRow to insert. The values record determines which columns are set.
Returns number
The last inserted row ID (the auto-generated primary key).
Example
```
const row = createUserRow(table, { name: 'New Feature' });
const newId = dao.insert(row);
console.log(`Inserted row with ID: ${newId}`);
```
Inherited from UserDao.insert
- Defined in src/user/user-dao.ts:135

queryById

queryById<T = Record<string, unknown>>(id: number): T | undefined
Queries a single row by its primary key value.
Type Parameters
- T = Record<string, unknown>
  The expected row type. Defaults to Record<string, unknown>.
Parameters
- id: number
  The primary key value to look up.
Returns T | undefined
The matching row, or undefined if no row with the given ID exists.
Example
```
const row = dao.queryById(42);
if (row) {
  console.log('Found:', row);
}
```
Inherited from UserDao.queryById
- Defined in src/user/user-dao.ts:114

queryForAll

queryForAll<T = Record<string, unknown>>(): IterableIterator<T>
Queries all rows from the table.

Returns a lazy iterable iterator that yields rows one at a time, which is memory-efficient for large tables.
Type Parameters
- T = Record<string, unknown>
  The expected row type. Defaults to Record<string, unknown>.
Returns IterableIterator<T>
An iterable iterator over all rows in the table.
Example
```
for (const row of dao.queryForAll()) {
  console.log(row);
}
```
Inherited from UserDao.queryForAll
- Defined in src/user/user-dao.ts:74

queryForGeoJSON

queryForGeoJSON(): IterableIterator<Feature<Geometry, GeoJsonProperties>>
Queries all features and yields them as GeoJSON Feature objects.

Iterates over every row in the feature table, converting each row's geometry blob to a GeoJSON geometry and mapping non-geometry, non-primary-key columns to the feature's properties.

Returns IterableIterator<Feature<Geometry, GeoJsonProperties>>
Yields
A GeoJSON Feature for each row in the table.
Example
```
const features: GeoJSON.Feature[] = [];
for (const feature of featureDao.queryForGeoJSON()) {
  features.push(feature);
}
```
- Defined in src/features/feature-dao.ts:128

queryForGeoJSONWithBoundingBox

queryForGeoJSONWithBoundingBox(
bbox: BoundingBox,
): IterableIterator<Feature<Geometry, GeoJsonProperties>>
Queries features within a bounding box and yields them as GeoJSON Feature objects.

Combines the spatial filtering of queryWithBoundingBox with the GeoJSON conversion of queryForGeoJSON, yielding GeoJSON Features for all rows whose geometries intersect the given bounding box.
Parameters
- bbox: BoundingBox
  The bounding box to filter features against.
Returns IterableIterator<Feature<Geometry, GeoJsonProperties>>
Yields
A GeoJSON Feature for each matching row.
Example
```
const bbox: BoundingBox = { minX: -74.1, minY: 40.6, maxX: -73.9, maxY: 40.8 };
for (const feature of featureDao.queryForGeoJSONWithBoundingBox(bbox)) {
  console.log(feature.geometry.type, feature.properties);
}
```
- Defined in src/features/feature-dao.ts:205

queryWhere

queryWhere<T = Record<string, unknown>>(
where: string,
...params: unknown[],
): IterableIterator<T>
Queries rows matching a SQL WHERE clause.

Returns a lazy iterable iterator that yields matching rows one at a time.
Type Parameters
- T = Record<string, unknown>
  The expected row type. Defaults to Record<string, unknown>.
Parameters
- where: string
  A SQL WHERE clause (without the WHERE keyword).
- ...params: unknown[]
  Bind parameters for placeholders in the WHERE clause.
Returns IterableIterator<T>
An iterable iterator over the matching rows.
Example
```
for (const row of dao.queryWhere('"status" = ?', 1)) {
  console.log(row);
}
```
Inherited from UserDao.queryWhere
- Defined in src/user/user-dao.ts:95

queryWithBoundingBox

queryWithBoundingBox(
bbox: BoundingBox,
): IterableIterator<Record<string, unknown>>
Queries features that intersect a bounding box.

If an R-tree spatial index exists for the feature table (named rtree_{tableName}_{geometryColumnName}), it is used for efficient spatial filtering via an index join. Otherwise, a full table scan is performed with envelope-based intersection checks on each geometry blob.
Parameters
- bbox: BoundingBox
  The bounding box to filter features against.
Returns IterableIterator<Record<string, unknown>>
Yields
Raw row records that intersect the bounding box.
Example
```
const bbox: BoundingBox = { minX: -74.1, minY: 40.6, maxX: -73.9, maxY: 40.8 };
for (const row of featureDao.queryWithBoundingBox(bbox)) {
  console.log(row);
}
```
- Defined in src/features/feature-dao.ts:153

update

update(row: UserRow): number
Updates an existing row in the table, identified by its primary key.

All columns present in row.values (except the primary key column itself) are updated. The primary key column value is used in the WHERE clause to identify the target row.
Parameters
- row: UserRow
  The UserRow containing updated values. Must include the primary key value.
Returns number
The number of rows affected by the update (typically 0 or 1).
Example
```
const row = createUserRow(table, { id: 42, name: 'Updated Name' });
const affected = dao.update(row);
console.log(`Updated ${affected} row(s)`);
```
Inherited from UserDao.update
- Defined in src/user/user-dao.ts:161

Class FeatureDao

Example

Hierarchy (View Summary)

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns FeatureDao

Properties

Protectedconn

Protectedtable

Accessors

geometryColumnName

Returns string

geometryType

Returns string

tableName

Returns string

Methods

count

Parameters

Returns number

Example

deleteById

Parameters

Returns number

Example

deleteWhere

Parameters

Returns number

Example

getBoundingBox

Returns BoundingBox | null

Example

getGeometryColumns

Returns GeometryColumns

getSrsId

Returns number

getTable

Returns UserTable

insert

Parameters

Returns number

Example

queryById

Type Parameters

Parameters

Returns T | undefined

Example

queryForAll

Type Parameters

Returns IterableIterator<T>

Example

queryForGeoJSON

Returns IterableIterator<Feature<Geometry, GeoJsonProperties>>

Yields

Example

queryForGeoJSONWithBoundingBox

Parameters

Returns IterableIterator<Feature<Geometry, GeoJsonProperties>>

Yields

Example

queryWhere

Type Parameters

Parameters

Returns IterableIterator<T>

Example

queryWithBoundingBox

Parameters

Returns IterableIterator<Record<string, unknown>>

Yields

Example

update

Parameters

Returns number

Example

`Protected`conn

`Protected`table