diff --git a/01.workspace/heave/src/fun/sqlite_build_statement.rs b/01.workspace/heave/src/fun/sqlite_build_statement.rs
index 5fee943..122a84f 100644
--- a/01.workspace/heave/src/fun/sqlite_build_statement.rs
+++ b/01.workspace/heave/src/fun/sqlite_build_statement.rs
@@ -25,65 +25,59 @@ fn from_condition(
 ) -> Result<String, FailedTo> {
     let fragment = match (comparison, condition) {
         // BOOL
-        (Comparison::Equal, Condition::Bool(_)) => compose_fragment(name, "value_bool", "=", i + 1),
+        (Comparison::Equal, Condition::Bool(_)) => compose_fragment(name, "value_bool", "=", i),
         (_, Condition::Bool(_)) => return Err(FailedTo::ComposeFilter),
         // SIGNED INT
-        (Comparison::Equal, Condition::SignedInt(_)) => {
-            compose_fragment(name, "value_int", "=", i + 1)
-        }
+        (Comparison::Equal, Condition::SignedInt(_)) => compose_fragment(name, "value_int", "=", i),
         (Comparison::Greater, Condition::SignedInt(_)) => {
-            compose_fragment(name, "value_int", ">", i + 1)
+            compose_fragment(name, "value_int", ">", i)
         }
         (Comparison::Lesser, Condition::SignedInt(_)) => {
-            compose_fragment(name, "value_int", "<", i + 1)
+            compose_fragment(name, "value_int", "<", i)
         }
         (Comparison::GreaterOrEqual, Condition::SignedInt(_)) => {
-            compose_fragment(name, "value_int", ">=", i + 1)
+            compose_fragment(name, "value_int", ">=", i)
         }
         (Comparison::LesserOrEqual, Condition::SignedInt(_)) => {
-            compose_fragment(name, "value_int", "<=", i + 1)
+            compose_fragment(name, "value_int", "<=", i)
         }
         (_, Condition::SignedInt(_)) => return Err(FailedTo::ComposeFilter),
         // UNSIGNED INT
         (Comparison::Equal, Condition::UnsignedInt(_)) => {
-            compose_fragment(name, "value_uint", "=", i + 1)
+            compose_fragment(name, "value_uint", "=", i)
         }
         (Comparison::Greater, Condition::UnsignedInt(_)) => {
-            compose_fragment(name, "value_uint", ">", i + 1)
+            compose_fragment(name, "value_uint", ">", i)
         }
         (Comparison::Lesser, Condition::UnsignedInt(_)) => {
-            compose_fragment(name, "value_uint", "<", i + 1)
+            compose_fragment(name, "value_uint", "<", i)
         }
         (Comparison::GreaterOrEqual, Condition::UnsignedInt(_)) => {
-            compose_fragment(name, "value_uint", ">=", i + 1)
+            compose_fragment(name, "value_uint", ">=", i)
         }
         (Comparison::LesserOrEqual, Condition::UnsignedInt(_)) => {
-            compose_fragment(name, "value_uint", "<=", i + 1)
+            compose_fragment(name, "value_uint", "<=", i)
         }
         (_, Condition::UnsignedInt(_)) => return Err(FailedTo::ComposeFilter),
         // REAL
-        (Comparison::Equal, Condition::Real(_)) => compose_fragment(name, "value_real", "=", i + 1),
-        (Comparison::Greater, Condition::Real(_)) => {
-            compose_fragment(name, "value_real", ">", i + 1)
-        }
-        (Comparison::Lesser, Condition::Real(_)) => {
-            compose_fragment(name, "value_real", "<", i + 1)
-        }
+        (Comparison::Equal, Condition::Real(_)) => compose_fragment(name, "value_real", "=", i),
+        (Comparison::Greater, Condition::Real(_)) => compose_fragment(name, "value_real", ">", i),
+        (Comparison::Lesser, Condition::Real(_)) => compose_fragment(name, "value_real", "<", i),
         (Comparison::GreaterOrEqual, Condition::Real(_)) => {
-            compose_fragment(name, "value_real", ">=", i + 1)
+            compose_fragment(name, "value_real", ">=", i)
         }
         (Comparison::LesserOrEqual, Condition::Real(_)) => {
-            compose_fragment(name, "value_real", "<=", i + 1)
+            compose_fragment(name, "value_real", "<=", i)
         }
         (_, Condition::Real(_)) => return Err(FailedTo::ComposeFilter),
         // TEXT
         (Comparison::IsExactly, Condition::Text(_)) => {
-            compose_fragment(name, "value_text", "LIKE", i + 1)
+            compose_fragment(name, "value_text", "LIKE", i)
         }
         (
             Comparison::StartsWith | Comparison::EndsWith | Comparison::Contains,
             Condition::Text(_),
-        ) => compose_fragment(name, "value_text", "LIKE", i + 1),
+        ) => compose_fragment(name, "value_text", "LIKE", i),
         (_, Condition::Text(_)) => return Err(FailedTo::ComposeFilter),
     };
     Ok(fragment)
@@ -95,8 +89,8 @@ pub fn run(filter: &Filter) -> Result<String, FailedTo> {
     let mut idx = 0;
     // for each condition add an inner join fragment
     for (i, (name, comparison, condition)) in filter.conditions().enumerate() {
-        idx = i;
-        let fragment = from_condition(i, name, comparison, condition)?;
+        idx = i + 1;
+        let fragment = from_condition(idx, name, comparison, condition)?;
         statement.push_str(&fragment);
     }
     // add a neutral where condition
diff --git a/01.workspace/heave/src/fun/sqlite_init_db.rs b/01.workspace/heave/src/fun/sqlite_init_db.rs
index 9c32f9c..9e4c44c 100644
--- a/01.workspace/heave/src/fun/sqlite_init_db.rs
+++ b/01.workspace/heave/src/fun/sqlite_init_db.rs
@@ -21,6 +21,7 @@ pub fn run(path: &path::Path) -> result::Result<(), FailedTo> {
             CONSTRAINT fk_entity_id FOREIGN KEY (entity_id) REFERENCES entity (id) ON DELETE CASCADE ON UPDATE CASCADE
         );
         CREATE INDEX IF NOT EXISTS entity_class ON entity (class);
+        CREATE INDEX IF NOT EXISTS entity_subclass ON entity (subclass);
         CREATE INDEX IF NOT EXISTS attribute_id ON attribute (id);
         "#;
     let connection = Connection::open(path).map_err(|_| sqlite::FailedTo::OpenConnection)?;