refactored ids from u32 to i64.

src/db/_securities.rs

@@ -34,7 +34,7 @@ impl ToSql for SecurityType {
 
 #[derive(Debug, Serialize, PartialEq)]
 pub struct Security {
-    id: u32,
+    id: i64,
     security_type: SecurityType,
     symbol: String,
 }