feat: implement fields for duckdb (#584)

- Closes #581

crates/api/CHANGELOG.md

@@ -8,7 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Added
 
-- Convenience methods on `Search` ([#562](https://github.com/stac-utils/stac-rs/pull/562))
+- Convenience methods on `Search` ([#562](https://github.com/stac-utils/stac-rs/pull/562), [#584](https://github.com/stac-utils/stac-rs/pull/584))
 
 ### Changed
 

crates/api/src/search.rs

@@ -1,4 +1,4 @@
-use crate::{Error, GetItems, Items, Result, Sortby};
+use crate::{Error, Fields, GetItems, Items, Result, Sortby};
 use geojson::Geometry;
 use serde::{Deserialize, Serialize};
 use serde_json::{Map, Value};
@@ -112,6 +112,12 @@ impl Search {
         self
     }
 
+    /// Sets the fields of this search.
+    pub fn fields(mut self, fields: Fields) -> Search {
+        self.items.fields = Some(fields);
+        self
+    }
+
     /// Returns an error if this search is invalid, e.g. if both bbox and intersects are specified.
     ///
     /// Returns the search unchanged if it is valid.

crates/duckdb/src/lib.rs

@@ -127,6 +127,7 @@ impl Client {
         // Get suffix information early so we can take ownership of other parts of search as we go along.
         let limit = search.items.limit.take();
         let sortby = std::mem::take(&mut search.items.sortby);
+        let fields = std::mem::take(&mut search.items.fields);
 
         let mut statement = self.connection.prepare(&format!(
             "SELECT column_name FROM (DESCRIBE SELECT * from read_parquet('{}'))",
@@ -138,17 +139,26 @@ impl Client {
         let mut has_end_datetime: bool = false;
         for row in statement.query_map([], |row| row.get::<_, String>(0))? {
             let column = row?;
-            if column == "geometry" {
-                columns.push("ST_AsWKB(geometry) geometry".to_string());
-                continue;
-            }
             if column == "start_datetime" {
                 has_start_datetime = true;
             }
             if column == "end_datetime" {
                 has_end_datetime = true;
             }
-            columns.push(format!("\"{}\"", column));
+
+            if let Some(fields) = fields.as_ref() {
+                if fields.exclude.contains(&column)
+                    || !(fields.include.is_empty() || fields.include.contains(&column))
+                {
+                    continue;
+                }
+            }
+
+            if column == "geometry" {
+                columns.push("ST_AsWKB(geometry) geometry".to_string());
+            } else {
+                columns.push(format!("\"{}\"", column));
+            }
         }
 
         let mut wheres = Vec::new();
@@ -419,4 +429,15 @@ mod tests {
             "S2B_MSIL2A_20241203T174629_R098_T13TDE_20241203T211406"
         );
     }
+
+    #[rstest]
+    fn search_fields(client: Client) {
+        let item_collection = client
+            .search_to_json(
+                "data/100-sentinel-2-items.parquet",
+                Search::default().fields("+id".parse().unwrap()).limit(1),
+            )
+            .unwrap();
+        assert_eq!(item_collection.items[0].len(), 1);
+    }
 }