src/core/interface/database/mod.rs

@@ -11,7 +11,7 @@ use crate::core::collection::{self, Collection};
 #[cfg_attr(test, automock)]
 pub trait IDatabase {
     /// Load collection from the database.
-    fn load(&self) -> Result<Collection, LoadError>;
+    fn load(&mut self) -> Result<Collection, LoadError>;
 
     /// Save collection to the database.
     fn save(&mut self, collection: &Collection) -> Result<(), SaveError>;
@@ -21,7 +21,7 @@ pub trait IDatabase {
 pub struct NullDatabase;
 
 impl IDatabase for NullDatabase {
-    fn load(&self) -> Result<Collection, LoadError> {
+    fn load(&mut self) -> Result<Collection, LoadError> {
         Ok(vec![])
     }
 
@@ -100,7 +100,7 @@ mod tests {
 
     #[test]
     fn null_database_load() {
-        let database = NullDatabase;
+        let mut database = NullDatabase;
         assert!(database.load().unwrap().is_empty());
     }
 

src/external/database/json/mod.rs

@@ -49,7 +49,7 @@ impl<JDB: IJsonDatabaseBackend> JsonDatabase<JDB> {
 }
 
 impl<JDB: IJsonDatabaseBackend> IDatabase for JsonDatabase<JDB> {
-    fn load(&self) -> Result<Collection, LoadError> {
+    fn load(&mut self) -> Result<Collection, LoadError> {
         let serialized = self.backend.read()?;
         let database: DeserializeDatabase = serde_json::from_str(&serialized)?;
         Ok(database.into())

src/external/database/serde/deserialize.rs

@@ -32,22 +32,22 @@ impl From<DeserializeDatabase> for Collection {
 
 #[derive(Debug, Deserialize)]
 pub struct DeserializeArtist {
-    name: String,
-    sort: Option<String>,
-    musicbrainz: DeserializeMbRefOption,
-    properties: HashMap<String, Vec<String>>,
-    albums: Vec<DeserializeAlbum>,
+    pub name: String,
+    pub sort: Option<String>,
+    pub musicbrainz: DeserializeMbRefOption,
+    pub properties: HashMap<String, Vec<String>>,
+    pub albums: Vec<DeserializeAlbum>,
 }
 
 #[derive(Debug, Deserialize)]
 pub struct DeserializeAlbum {
-    title: String,
-    lib_id: SerdeAlbumLibId,
-    date: SerdeAlbumDate,
-    seq: u8,
-    musicbrainz: DeserializeMbRefOption,
-    primary_type: Option<SerdeAlbumPrimaryType>,
-    secondary_types: Vec<SerdeAlbumSecondaryType>,
+    pub title: String,
+    pub lib_id: SerdeAlbumLibId,
+    pub date: SerdeAlbumDate,
+    pub seq: u8,
+    pub musicbrainz: DeserializeMbRefOption,
+    pub primary_type: Option<SerdeAlbumPrimaryType>,
+    pub secondary_types: Vec<SerdeAlbumSecondaryType>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -110,6 +110,8 @@ impl<'de> Deserialize<'de> for DeserializeMbid {
 
 impl From<DeserializeArtist> for Artist {
     fn from(artist: DeserializeArtist) -> Self {
+        let mut albums: Vec<Album> = artist.albums.into_iter().map(Into::into).collect();
+        albums.sort_unstable();
         Artist {
             meta: ArtistMeta {
                 id: ArtistId {
@@ -121,7 +123,7 @@ impl From<DeserializeArtist> for Artist {
                     properties: artist.properties,
                 },
             },
-            albums: artist.albums.into_iter().map(Into::into).collect(),
+            albums,
         }
     }
 }

src/external/database/serde/mod.rs

@@ -1,5 +1,5 @@
 //! Helper module for backends that can use serde for (de)serialisation.
 
-mod common;
+pub mod common;
 pub mod deserialize;
 pub mod serialize;

src/external/database/sql/backend.rs

@@ -2,11 +2,20 @@
 
 use std::path::PathBuf;
 
-use rusqlite::{self, CachedStatement, Connection, Params, Statement, Transaction};
+use rusqlite::{
+    self, types::FromSql, CachedStatement, Connection, Params, Row, Rows, Statement, Transaction,
+};
 
-use crate::external::database::{
-    serde::serialize::{SerializeAlbum, SerializeArtist, SerializeDatabase},
+use crate::{
+    collection::album::AlbumDate,
+    external::database::{
+        serde::{
+            common::SerdeAlbumDate,
+            deserialize::{DeserializeAlbum, DeserializeArtist, DeserializeDatabase},
+            serialize::{SerializeAlbum, SerializeArtist, SerializeDatabase},
+        },
         sql::{Error, ISqlDatabaseBackend, ISqlTransactionBackend},
+    },
 };
 
 /// SQLite database backend that uses SQLite as the implementation.
@@ -45,6 +54,21 @@ impl<'conn> SqlTransactionSqliteBackend<'conn> {
             .map(|_| ())
             .map_err(|err| Error::ExecError(err.to_string()))
     }
+
+    fn query<'s, P: Params>(stmt: &'s mut Statement, params: P) -> Result<Rows<'s>, Error> {
+        stmt.query(params)
+            .map_err(|err| Error::ExecError(err.to_string()))
+    }
+
+    fn next_row<'r, 's>(rows: &'r mut Rows<'s>) -> Result<Option<&'r Row<'s>>, Error> {
+        rows.next()
+            .map_err(|err| Error::SerDeError(err.to_string()))
+    }
+
+    fn get_value<T: FromSql>(row: &Row<'_>, idx: usize) -> Result<T, Error> {
+        row.get(idx)
+            .map_err(|err| Error::SerDeError(err.to_string()))
+    }
 }
 
 impl From<serde_json::Error> for Error {
@@ -116,7 +140,7 @@ impl<'conn> ISqlTransactionBackend for SqlTransactionSqliteBackend<'conn> {
                  seq INT NOT NULL,
                  primary_type JSON NOT NULL DEFAULT 'null',
                  secondary_types JSON NOT NULL DEFAULT '[]',
-                 FOREIGN KEY (artist_name) REFERENCES artists(name)
+                 FOREIGN KEY (artist_name) REFERENCES artists(name) ON DELETE CASCADE ON UPDATE NO ACTION
              )",
         )?;
         Self::execute(&mut stmt, ())
@@ -138,6 +162,25 @@ impl<'conn> ISqlTransactionBackend for SqlTransactionSqliteBackend<'conn> {
         Self::execute(&mut stmt, ("version", version))
     }
 
+    fn select_database_version<'a>(&self) -> Result<DeserializeDatabase, Error> {
+        let mut stmt =
+            self.prepare_cached("SELECT value FROM database_metadata WHERE name = 'version'")?;
+        let mut rows = Self::query(&mut stmt, ())?;
+
+        match Self::next_row(&mut rows)? {
+            Some(row) => {
+                let version: String = Self::get_value(&row, 0)?;
+                match version.as_str() {
+                    "V20250103" => Ok(DeserializeDatabase::V20250103(vec![])),
+                    s @ _ => Err(Error::SerDeError(format!("unknown database version: {s}"))),
+                }
+            }
+            None => Err(Error::SerDeError(String::from(
+                "database version is missing",
+            ))),
+        }
+    }
+
     fn insert_artist<'a>(&self, artist: &SerializeArtist<'a>) -> Result<(), Error> {
         let mut stmt = self.prepare_cached(
             "INSERT INTO artists (name, sort, mbid, properties)
@@ -154,6 +197,24 @@ impl<'conn> ISqlTransactionBackend for SqlTransactionSqliteBackend<'conn> {
         )
     }
 
+    fn select_all_artists(&self) -> Result<Vec<DeserializeArtist>, Error> {
+        let mut stmt = self.prepare_cached("SELECT name, sort, mbid, properties FROM artists")?;
+        let mut rows = Self::query(&mut stmt, ())?;
+
+        let mut artists = vec![];
+        while let Some(row) = Self::next_row(&mut rows)? {
+            artists.push(DeserializeArtist {
+                name: Self::get_value(row, 0)?,
+                sort: Self::get_value(row, 1)?,
+                musicbrainz: serde_json::from_str(&Self::get_value::<String>(row, 2)?)?,
+                properties: serde_json::from_str(&Self::get_value::<String>(row, 3)?)?,
+                albums: vec![],
+            });
+        }
+
+        Ok(artists)
+    }
+
     fn insert_album<'a>(&self, artist_name: &str, album: &SerializeAlbum<'a>) -> Result<(), Error> {
         let mut stmt = self.prepare_cached(
             "INSERT INTO albums (title, lib_id, mbid, artist_name,
@@ -176,4 +237,31 @@ impl<'conn> ISqlTransactionBackend for SqlTransactionSqliteBackend<'conn> {
             ),
         )
     }
+
+    fn select_artist_albums(&self, artist_name: &str) -> Result<Vec<DeserializeAlbum>, Error> {
+        let mut stmt = self.prepare_cached(
+            "SELECT title, lib_id, year, month, day, seq, mbid, primary_type, secondary_types
+             FROM albums WHERE artist_name = ?1",
+        )?;
+        let mut rows = Self::query(&mut stmt, [artist_name])?;
+
+        let mut albums = vec![];
+        while let Some(row) = Self::next_row(&mut rows)? {
+            albums.push(DeserializeAlbum {
+                title: Self::get_value(row, 0)?,
+                lib_id: serde_json::from_str(&Self::get_value::<String>(row, 1)?)?,
+                date: SerdeAlbumDate(AlbumDate::new(
+                    Self::get_value(row, 2)?,
+                    Self::get_value(row, 3)?,
+                    Self::get_value(row, 4)?,
+                )),
+                seq: Self::get_value(row, 5)?,
+                musicbrainz: serde_json::from_str(&Self::get_value::<String>(row, 6)?)?,
+                primary_type: serde_json::from_str(&Self::get_value::<String>(row, 7)?)?,
+                secondary_types: serde_json::from_str(&Self::get_value::<String>(row, 8)?)?,
+            });
+        }
+
+        Ok(albums)
+    }
 }

src/external/database/sql/mod.rs

@@ -12,7 +12,10 @@ use crate::{
         collection::Collection,
         interface::database::{IDatabase, LoadError, SaveError},
     },
-    external::database::serde::serialize::{SerializeAlbum, SerializeArtist, SerializeDatabase},
+    external::database::serde::{
+        deserialize::{DeserializeAlbum, DeserializeArtist, DeserializeDatabase},
+        serialize::{SerializeAlbum, SerializeArtist, SerializeDatabase},
+    },
 };
 
 /// Trait for the SQL database backend.
@@ -50,11 +53,20 @@ pub trait ISqlTransactionBackend {
     /// Set the database version.
     fn insert_database_version<'a>(&self, version: &SerializeDatabase<'a>) -> Result<(), Error>;
 
+    /// Get the database version.
+    fn select_database_version<'a>(&self) -> Result<DeserializeDatabase, Error>;
+
     /// Insert an artist into the artist table.
     fn insert_artist<'a>(&self, artist: &SerializeArtist<'a>) -> Result<(), Error>;
 
+    /// Get all artists from the artist table.
+    fn select_all_artists(&self) -> Result<Vec<DeserializeArtist>, Error>;
+
     /// Insert an artist into the artist table.
     fn insert_album<'a>(&self, artist_name: &str, album: &SerializeAlbum<'a>) -> Result<(), Error>;
+
+    /// Get all albums from the album table.
+    fn select_artist_albums(&self, artist_name: &str) -> Result<Vec<DeserializeAlbum>, Error>;
 }
 
 /// Errors for SQL database backend.
@@ -95,6 +107,15 @@ impl From<Error> for SaveError {
     }
 }
 
+impl From<Error> for LoadError {
+    fn from(value: Error) -> Self {
+        match value {
+            Error::SerDeError(s) => LoadError::SerDeError(s),
+            _ => LoadError::IoError(value.to_string()),
+        }
+    }
+}
+
 /// SQL database.
 pub struct SqlDatabase<SDB> {
     backend: SDB,
@@ -127,8 +148,21 @@ impl<SDB: for<'conn> ISqlDatabaseBackend<'conn>> SqlDatabase<SDB> {
 }
 
 impl<SDB: for<'conn> ISqlDatabaseBackend<'conn>> IDatabase for SqlDatabase<SDB> {
-    fn load(&self) -> Result<Collection, LoadError> {
-        Ok(vec![])
+    fn load(&mut self) -> Result<Collection, LoadError> {
+        let tx = self.backend.transaction()?;
+
+        let mut database = tx.select_database_version()?;
+        match database {
+            DeserializeDatabase::V20250103(ref mut coll) => {
+                coll.extend(tx.select_all_artists()?);
+                for artist in coll.iter_mut() {
+                    artist.albums.extend(tx.select_artist_albums(&artist.name)?);
+                }
+            }
+        }
+
+        tx.commit()?;
+        Ok(database.into())
     }
 
     fn save(&mut self, collection: &Collection) -> Result<(), SaveError> {

src/external/musicbrainz/api/mod.rs

@@ -227,7 +227,7 @@ impl<'de> Deserialize<'de> for SerdeMbid {
 }
 
 #[derive(Debug, Clone)]
-pub struct SerdeAlbumDate(AlbumDate);
+pub struct SerdeAlbumDate(pub AlbumDate);
 
 impl From<SerdeAlbumDate> for AlbumDate {
     fn from(value: SerdeAlbumDate) -> Self {

tests/database/json.rs

@@ -43,7 +43,7 @@ fn save() {
 #[test]
 fn load() {
     let backend = JsonDatabaseFileBackend::new(&*DATABASE_TEST_FILE);
-    let database = JsonDatabase::new(backend);
+    let mut database = JsonDatabase::new(backend);
 
     let read_data: Vec<Artist> = database.load().unwrap();
 

tests/database/sql.rs

@@ -3,64 +3,61 @@ use std::{fs, path::PathBuf};
 use once_cell::sync::Lazy;
 
 use musichoard::{
+    collection::{artist::Artist, Collection},
     external::database::sql::{backend::SqlDatabaseSqliteBackend, SqlDatabase},
     interface::database::IDatabase,
 };
+use tempfile::NamedTempFile;
 
 use crate::testlib::COLLECTION;
 
 pub static DATABASE_TEST_FILE: Lazy<PathBuf> =
     Lazy::new(|| fs::canonicalize("./tests/files/database/database.db").unwrap());
 
-// fn expected() -> Collection {
-//     let mut expected = COLLECTION.to_owned();
-//     for artist in expected.iter_mut() {
-//         for album in artist.albums.iter_mut() {
-//             album.tracks.clear();
-//         }
-//     }
-//     expected
-// }
+fn expected() -> Collection {
+    let mut expected = COLLECTION.to_owned();
+    for artist in expected.iter_mut() {
+        for album in artist.albums.iter_mut() {
+            album.tracks.clear();
+        }
+    }
+    expected
+}
 
 #[test]
 fn save() {
-    // let file = NamedTempFile::new().unwrap();
+    let file = NamedTempFile::new().unwrap();
 
-    let backend = SqlDatabaseSqliteBackend::new(&*DATABASE_TEST_FILE).unwrap();
+    let backend = SqlDatabaseSqliteBackend::new(file.path()).unwrap();
     let mut database = SqlDatabase::new(backend).unwrap();
 
     let write_data = COLLECTION.to_owned();
     database.save(&write_data).unwrap();
-
-    // let expected = fs::read_to_string(&*DATABASE_TEST_FILE).unwrap();
-    // let actual = fs::read_to_string(file.path()).unwrap();
-
-    // assert_eq!(actual, expected);
 }
 
-// #[test]
-// fn load() {
-//     let backend = JsonDatabaseFileBackend::new(&*DATABASE_TEST_FILE);
-//     let database = JsonDatabase::new(backend);
+#[test]
+fn load() {
+    let backend = SqlDatabaseSqliteBackend::new(&*DATABASE_TEST_FILE).unwrap();
+    let mut database = SqlDatabase::new(backend).unwrap();
 
-//     let read_data: Vec<Artist> = database.load().unwrap();
+    let read_data: Vec<Artist> = database.load().unwrap();
 
-//     let expected = expected();
-//     assert_eq!(read_data, expected);
-// }
+    let expected = expected();
+    assert_eq!(read_data, expected);
+}
 
-// #[test]
-// fn reverse() {
-//     let file = NamedTempFile::new().unwrap();
+#[test]
+fn reverse() {
+    let file = NamedTempFile::new().unwrap();
 
-//     let backend = JsonDatabaseFileBackend::new(file.path());
-//     let mut database = JsonDatabase::new(backend);
+    let backend = SqlDatabaseSqliteBackend::new(file.path()).unwrap();
+    let mut database = SqlDatabase::new(backend).unwrap();
 
-//     let write_data = COLLECTION.to_owned();
-//     database.save(&write_data).unwrap();
-//     let read_data: Vec<Artist> = database.load().unwrap();
+    let write_data = COLLECTION.to_owned();
+    database.save(&write_data).unwrap();
+    let read_data: Vec<Artist> = database.load().unwrap();
 
-//     // Album data is not saved into database.
-//     let expected = expected();
-//     assert_eq!(read_data, expected);
-// }
+    // Not all data is saved into database.
+    let expected = expected();
+    assert_eq!(read_data, expected);
+}