lazysf

• sql_translation(), sql_escape_logical(), and sql_query_fields() now dispatch on a custom dialect class (sql_dialect_gdal_vector / sql_dialect_gdal_sqlite) rather than the connection class, matching how dbplyr 2.6.0 dispatches these generics.
• Identifier quoting now uses double quotes (ANSI SQL) rather than backticks. GDAL's embedded SQLite engine rejects backtick-quoted identifiers generated by dbplyr 2.6.0's default SQLite dialect.
• supports_window_clause() was removed from dbplyr 2.6.0; it is now conditionally registered only when the generic exists.
• Spatial SQL translations (SpatiaLite functions) are gated on dialect: SQLITE connections get full spatial translations, OGRSQL connections get base translations only.

New features

• New geom_format argument to dbConnect() controls geometry output: "WKB" (default), "WKT", "NONE", or "BBOX". Configurable globally via options(lazysf.geom_format = ...).
• New dialect argument to dbConnect() controls SQL dialect: "SQLITE" (the default), "OGRSQL", "INDIRECT_SQLITE", or "" (let GDAL choose). SQLITE is the default because it supports subqueries (required for dbplyr verb chaining) and spatial SQL functions like ST_Area(). Configurable globally via options(lazysf.dialect = ...).
• lazysf() now passes ... through to dbConnect(), so geom_format and dialect can be set directly: lazysf(dsn, geom_format = "WKT").
• Added db_connection_describe() method for informative printing: GDAL <SQLITE> WKB [/path/to/file.gpkg].
• New sql_query_fields() method generates LIMIT 0 SQL for field discovery (replacing dbplyr's default WHERE (0 = 1) which OGRSQL can't handle). For named tables, dbSendQuery() intercepts this and uses $getLayerDefn() for pure OGR metadata access — no SQL execution at all. Subqueries are correctly wrapped in parentheses with an alias.
• New .schema_from_defn() builds typed empty data frames from OGR layer definitions, mapping OGR field types to R types (OFTInteger → integer, OFTReal → double, OFTDateTime → POSIXct, OFSTBoolean → logical, etc.). Schema column names and types match what fetch() returns.
• New dbListFields() method uses $getLayerDefn() for schema introspection without executing SQL.
• Geometry columns are now automatically marked with wk types on materialization: wk::wkb() for WKB, wk::wkt() for WKT, and wk::rct() for BBOX. CRS from the layer's spatial reference is attached to all geometry vectors.
• New sql_translation() method provides SpatiaLite function translations for the SQLITE dialect. R functions like st_area(), st_intersects(), st_buffer(), st_transform() etc. translate to their SpatiaLite SQL equivalents, enabling idiomatic dplyr pipelines with spatial operations: lazysf("countries.gpkg") |> filter(st_area(geom) > 1e6). OGRSQL dialect falls back to base SQLite translations only.
• Added sql_escape_logical() method: TRUE/FALSE map to 1/0 for SQLite, NA maps to NULL.
• Added supports_window_clause() method (returns TRUE for SQLITE dialect).
• Future-proofed for upcoming dbplyr sql_dialect() generic. When the next version of dbplyr ships with the new dialect system, lazysf will automatically provide SQLite translation without any code changes.
• New use_arrow argument to dbConnect() and lazysf() enables GDAL's Arrow C stream interface for reading features. Columnar transfer via GDALVector$getArrowStream() and nanoarrow, typically much faster for larger datasets. Requires GDAL >= 3.6. Configurable globally via options(lazysf.use_arrow = ...).
• Geometry columns are automatically marked with wk types on materialization. CRS is attached. This enables sf::st_as_sf() on the collected tibble via sf's wk support without any lazysf-specific method.

Bug fixes

• Multiline SQL from dbplyr is now collapsed to a single line before passing to GDALVector. GDAL's constructor rejects SQL with newline characters, which dbplyr generates for rename(), transmute(), and any verb that enumerates columns explicitly.
• Table-qualified column prefixes from GDAL (e.g. nc.AREA from SELECT "nc".*) are now stripped automatically so column names match what dbplyr expects.
• OGRFeatureSet class is stripped from fetch results. The gdalraster print method for this class conflicts with wk-typed geometry columns.
• FID column name is normalized to uppercase "FID" in both the fetch() and Arrow paths, matching GDAL's behavior (GeoPackage stores "fid" but fetch() returns "FID").
• Geometry column from getLayerDefn() is excluded from the attribute field loop in .schema_from_defn() — getLayerDefn() includes geometry as a field but fetch() handles it separately via returnGeomAs.

Known issues

• GDAL's GDALVector initialization emits "SpatiaLite is not available" warnings on systems without SpatiaLite linked. These are harmless C++ diagnostics that can't be suppressed from R. Tracked upstream in gdalraster.
• No window functions: slice_min(), slice_max(), row_number() etc. are not supported by GDAL's SQLite engine. Use arrange() |> head() instead.
• Spatial SQL function availability depends on GDAL build configuration. ST_Area() and ST_SRID() work without SpatiaLite (GDAL-native). ST_AsText(), ST_Intersects(), and most geometry operations require SpatiaLite.

Dependencies

• gdalraster (>= 2.0.0) replaces sf in Imports.
• wk added to Imports for geometry type marking.
• sf removed from dependencies (was previously in Imports, then Suggests).
• nanoarrow added to Suggests (for Arrow stream interface).
• dbplyr (>= 2.0.0) now required (2nd edition backend API).
• magrittr removed from dependencies.