diff --git a/src/persist/sqlite_manager.rs b/src/persist/sqlite_manager.rs
index f3ace8a..ef46186 100644
--- a/src/persist/sqlite_manager.rs
+++ b/src/persist/sqlite_manager.rs
@@ -24,7 +24,7 @@ impl SqliteManager {
 
   // The order of the items is undefined.
   pub async fn films_overview(&self) -> Result<Vec<FilmOverview>, DataManagerError> {
-    let overview = self
+    self
       .client
       .conn(|connection| {
         connection
@@ -33,38 +33,18 @@ impl SqliteManager {
               select uuid, name, original_name, release_date, runtime_minutes
                 from films
             ",
-          )
-          .expect("films overview statement should be valid SQL")
-          .query(())
-          .expect("parameters in films overview query should match those in its statement")
+          )?
+          .query(())?
           .map(row_to_film_overview)
           .collect()
       })
-      .await;
-
-    overview.map_err(|async_sqlite_error| match async_sqlite_error {
-      async_sqlite::Error::Closed => {
-        panic!("database connection should remain open as long as the application is running")
-      }
-      async_sqlite::Error::Rusqlite(rusqlite_error) => match rusqlite_error {
-        rusqlite::Error::InvalidColumnIndex(_) => {
-          panic!("column indices obtained from films overview query should exist")
-        }
-        rusqlite::Error::InvalidColumnName(_) => {
-          panic!("column names obtained from films overview query should exist")
-        }
-        rusqlite::Error::InvalidColumnType(..) => panic!(
-          "values obtained from films overview query should have a type matching their column"
-        ),
-        _ => DataManagerError::UnknownDBError,
-      },
-      _ => DataManagerError::UnknownDBError,
-    })
+      .await
+      .map_err(convert_error)
   }
 
   // The order of the items is undefined.
   pub async fn series_overview(&self) -> Result<Vec<SeriesOverview>, DataManagerError> {
-    let overview = self
+    self
       .client
       .conn(|connection| {
         connection
@@ -76,33 +56,13 @@ impl SqliteManager {
               where series.uuid = seasons.series and seasons.uuid = episodes.season
               group by series.uuid
             ",
-          )
-          .expect("series overview statement should be valid SQL")
-          .query(())
-          .expect("parameters in series overview query should match those in its statement")
+          )?
+          .query(())?
           .map(row_to_series_overview)
           .collect()
       })
-      .await;
-
-    overview.map_err(|async_sqlite_error| match async_sqlite_error {
-      async_sqlite::Error::Closed => {
-        panic!("database connection should remain open as long as the application is running")
-      }
-      async_sqlite::Error::Rusqlite(rusqlite_error) => match rusqlite_error {
-        rusqlite::Error::InvalidColumnIndex(_) => {
-          panic!("column indices obtained from series overview query should exist")
-        }
-        rusqlite::Error::InvalidColumnName(_) => {
-          panic!("column names obtained from series overview query should exist")
-        }
-        rusqlite::Error::InvalidColumnType(..) => panic!(
-          "values obtained from series overview query should have a type matching their column"
-        ),
-        _ => DataManagerError::UnknownDBError,
-      },
-      _ => DataManagerError::UnknownDBError,
-    })
+      .await
+      .map_err(convert_error)
   }
 }
 
@@ -128,21 +88,13 @@ async fn create_client(data_dir: &OsStr) -> Result<Client, DataManagerError> {
           let shared_path = shared_path_os_str
             .to_str()
             .expect("shared database path should be valid Unicode");
-          connection
-            .execute("attach database :path as shared", &[(":path", shared_path)])
-            .expect(
-              "shared database attaching statement should be valid SQL with matching parameters",
-            );
+          connection.execute("attach database :path as shared", &[(":path", shared_path)])?;
 
           let local_path_os_str = concat_os_str!(&data_dir, "/local.sqlite");
           let local_path = local_path_os_str
             .to_str()
             .expect("local database path should be valid Unicode");
-          connection
-            .execute("attach database :path as local", &[(":path", local_path)])
-            .expect(
-              "local database attaching statement should be valid SQL with matching parameters",
-            );
+          connection.execute("attach database :path as local", &[(":path", local_path)])?;
 
           Ok(())
         })
@@ -151,19 +103,7 @@ async fn create_client(data_dir: &OsStr) -> Result<Client, DataManagerError> {
     })
     .await;
 
-  client.map_err(|async_sqlite_error| match async_sqlite_error {
-    async_sqlite::Error::Closed => {
-      panic!("database connection should remain open as long as the application is running")
-    }
-    async_sqlite::Error::Rusqlite(rusqlite_error) => match rusqlite_error {
-      rusqlite::Error::SqliteFailure(sqlite_error, _) => match sqlite_error.code {
-        rusqlite::ffi::ErrorCode::CannotOpen => DataManagerError::CannotOpenDB,
-        _ => DataManagerError::UnknownDBError,
-      },
-      _ => DataManagerError::UnknownDBError,
-    },
-    _ => DataManagerError::UnknownDBError,
-  })
+  client.map_err(convert_error)
 }
 
 fn row_to_film_overview(row: &Row) -> rusqlite::Result<FilmOverview> {
@@ -196,8 +136,36 @@ fn row_to_series_overview(row: &Row) -> rusqlite::Result<SeriesOverview> {
   })
 }
 
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
-enum DBType {
-  Shared,
-  Local,
+fn convert_error(async_sqlite_error: async_sqlite::Error) -> DataManagerError {
+  match async_sqlite_error {
+    async_sqlite::Error::Closed => {
+      panic!("database connection should remain open as long as the application is running")
+    }
+    async_sqlite::Error::Rusqlite(rusqlite_error) => match rusqlite_error {
+      rusqlite::Error::SqliteFailure(sqlite_error, _) => match sqlite_error.code {
+        rusqlite::ffi::ErrorCode::CannotOpen => DataManagerError::CannotOpenDB,
+        _ => DataManagerError::UnknownDBError,
+      },
+      rusqlite::Error::InvalidColumnIndex(_) => {
+        panic!("column indices obtained from query should exist")
+      }
+      rusqlite::Error::InvalidColumnName(_) => {
+        panic!("column names obtained from query should exist")
+      }
+      rusqlite::Error::InvalidColumnType(..) => {
+        panic!("values obtained from query should have a type matching their column")
+      }
+      rusqlite::Error::InvalidParameterCount(..) => {
+        panic!("number of bound parameters should match that in the statement")
+      }
+      rusqlite::Error::ExecuteReturnedResults => {
+        panic!("execution of statement returned data when it shouldn't")
+      }
+      rusqlite::Error::MultipleStatement => {
+        panic!("multiple statements present when there should be one")
+      }
+      _ => DataManagerError::UnknownDBError,
+    },
+    _ => DataManagerError::UnknownDBError,
+  }
 }