Add SQL query to count children by user: Introduced a new query to count distinct children associated with a user across all their characters. Updated UserCharacterWorker to utilize this new query, replacing the previous count query. This enhances user-specific data retrieval capabilities.

src/worker/sql.rs

@@ -580,6 +580,14 @@ pub const QUERY_COUNT_CHILDREN: &str = r#"
 SELECT COUNT(*) AS cnt FROM falukant_data.child_relation WHERE (father_character_id = $1 OR mother_character_id = $1) AND child_character_id != $2;
 "#;
 
+/// Zählt Kinder eines Users (über alle Charaktere des Users als Elternteil). Ein Parameter: user_id.
+pub const QUERY_COUNT_CHILDREN_BY_USER: &str = r#"
+SELECT COUNT(DISTINCT cr.child_character_id) AS cnt
+FROM falukant_data.child_relation cr
+JOIN falukant_data.character parent ON (parent.id = cr.father_character_id OR parent.id = cr.mother_character_id)
+WHERE parent.user_id = $1;
+"#;
+
 // user_character worker queries
 pub const QUERY_GET_USERS_TO_UPDATE: &str = r#"
         SELECT id, CURRENT_DATE - birthdate::date AS age, health