added limit 1 to arrays treated as a single value in schemas

src/database/compile/mod.rs

@@ -7,7 +7,6 @@ pub mod polymorphism;
 use crate::database::schema::Schema;
 use crate::drop::{Error, ErrorDetails};
 use indexmap::IndexMap;
-use std::collections::HashMap;
 
 impl Schema {
   pub fn compile(
@@ -64,7 +63,7 @@ impl Schema {
       if custom_type_count > 1 {
         errors.push(Error {
           code: "MULTIPLE_INHERITANCE_PROHIBITED".to_string(),
-          values: Some(HashMap::from([("types".to_string(), types.join(", "))])),
+          values: Some(IndexMap::from([("types".to_string(), types.join(", "))])),
           details: ErrorDetails {
             path: Some(path.clone()),
             schema: Some(root_id.to_string()),