admin: Can list independant exercices as theme

libfic/exercice.go

@@ -645,3 +645,14 @@ func (e *Exercice) IsSolved() (int, *time.Time) {
 		return *nb, tm
 	}
 }
+
+func HasStandaloneExercice() (bool, error) {
+	var nb int
+
+	err := DBQueryRow("SELECT COUNT(id_exercice) FROM exercices WHERE id_theme IS NULL").Scan(&nb)
+	if err != nil {
+		return false, err
+	} else {
+		return nb > 0, nil
+	}
+}