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

src/queryer/compiler.rs

@@ -240,7 +240,7 @@ impl<'a> Compiler<'a> {
     };
 
     // 3. Build WHERE clauses
-    let where_clauses = self.compile_where_clause(r#type, &table_aliases, node)?;
+    let where_clauses = self.compile_where_clause(r#type, &table_aliases, node.clone())?;
 
     let selection = if is_array {
       format!("COALESCE(jsonb_agg({}), '[]'::jsonb)", jsonb_obj_sql)
@@ -248,11 +248,38 @@ impl<'a> Compiler<'a> {
       jsonb_obj_sql
     };
 
+    let mut limit_clause = "";
+    if !is_array {
+      let is_reverse = if let Some(prop_ref) = &node.property_name {
+        let prop = prop_ref.as_str();
+        if let Some(parent_schema) = &node.parent_schema {
+          if let Some(compiled_edges) = parent_schema.obj.compiled_edges.get() {
+            if let Some(edge) = compiled_edges.get(prop) {
+              !edge.forward
+            } else {
+              false
+            }
+          } else {
+            false
+          }
+        } else {
+          false
+        }
+      } else {
+        false
+      };
+
+      if is_reverse {
+        limit_clause = " LIMIT 1";
+      }
+    }
+
     let full_sql = format!(
-      "(SELECT {} FROM {} WHERE {})",
+      "(SELECT {} FROM {} WHERE {}{})",
       selection,
       from_clauses.join(" "),
-      where_clauses.join(" AND ")
+      where_clauses.join(" AND "),
+      limit_clause
     );
 
     Ok((

src/queryer/mod.rs

@@ -1,6 +1,6 @@
 use crate::database::Database;
 use crate::drop::{Drop, Error, ErrorDetails};
-use std::collections::HashMap;
+use indexmap::IndexMap;
 use std::sync::Arc;
 
 pub mod compiler;
@@ -33,7 +33,7 @@ impl Queryer {
       Err(msg) => {
         return Drop::with_errors(vec![Error {
           code: "FILTER_PARSE_FAILED".to_string(),
-          values: Some(HashMap::from([
+          values: Some(IndexMap::from([
             ("error".to_string(), msg.clone()),
           ])),
           details: ErrorDetails {
@@ -140,7 +140,7 @@ impl Queryer {
       }
       Err(e) => Err(Drop::with_errors(vec![Error {
         code: "QUERY_COMPILATION_FAILED".to_string(),
-        values: Some(HashMap::from([
+        values: Some(IndexMap::from([
           ("error".to_string(), e.clone()),
         ])),
         details: ErrorDetails {
@@ -169,7 +169,7 @@ impl Queryer {
       }
       Ok(other) => Drop::with_errors(vec![Error {
         code: "QUERY_FAILED".to_string(),
-        values: Some(HashMap::from([
+        values: Some(IndexMap::from([
           ("error".to_string(), format!("Expected array from generic query, got: {:?}", other)),
         ])),
         details: ErrorDetails {
@@ -181,7 +181,7 @@ impl Queryer {
       }]),
       Err(e) => Drop::with_errors(vec![Error {
         code: "QUERY_FAILED".to_string(),
-        values: Some(HashMap::from([
+        values: Some(IndexMap::from([
           ("error".to_string(), e.to_string()),
         ])),
         details: ErrorDetails {