postgres indexer fix

collections/codec/indexing.go

@@ -81,20 +81,20 @@ func FallbackSchemaCodec[T any]() SchemaCodec[T] {
 			FromSchemaType: nil,
 		}
 	} else {
-		// we default to encoding everything to JSON
+		// we default to encoding everything to String
 		return SchemaCodec[T]{
-			Fields: []schema.Field{{Kind: schema.JSONKind}},
+			Fields: []schema.Field{{Kind: schema.StringKind}},
 			ToSchemaType: func(t T) (any, error) {
 				bz, err := json.Marshal(t)
-				return json.RawMessage(bz), err
+				return string(json.RawMessage(bz)), err
 			},
 			FromSchemaType: func(a any) (T, error) {
 				var t T
-				bz, ok := a.(json.RawMessage)
+				sz, ok := a.(string)
 				if !ok {
-					return t, fmt.Errorf("expected json.RawMessage, got %T", a)
+					return t, fmt.Errorf("expected string, got %T", a)
 				}
-				err := json.Unmarshal(bz, &t)
+				err := json.Unmarshal([]byte(sz), &t)
 				return t, err
 			},
 		}

collections/indexing.go

@@ -133,6 +133,9 @@ func (c collectionImpl[K, V]) schemaCodec() (*collectionSchemaCodec, error) {
 		if err != nil {
 			return nil, err
 		}
+		if keyDecoder.ToSchemaType == nil {
+			return x, nil
+		}
 		return keyDecoder.ToSchemaType(x)
 	}
 	ensureFieldNames(c.m.kc, "key", res.objectType.KeyFields)

collections/pair.go

@@ -33,6 +33,11 @@ func (p Pair[K1, K2]) K2() (k2 K2) {
 	return *p.key2
 }
 
+// Keys returns key1 and key2 as a slice.
+func (p Pair[K1, K2]) Keys() []interface{} {
+	return []interface{}{p.K1(), p.K2()}
+}
+
 // Join creates a new Pair instance composed of the two provided keys, in order.
 func Join[K1, K2 any](key1 K1, key2 K2) Pair[K1, K2] {
 	return Pair[K1, K2]{

indexer/postgres/params.go

@@ -8,6 +8,11 @@ import (
 	"cosmossdk.io/schema"
 )
 
+type keyCollection interface {
+	// Keys returns the key fields for the collection.
+	Keys() []interface{}
+}
+
 // bindKeyParams binds the key to the key columns.
 func (tm *objectIndexer) bindKeyParams(key interface{}) ([]interface{}, []string, error) {
 	n := len(tm.typ.KeyFields)
@@ -17,6 +22,9 @@ func (tm *objectIndexer) bindKeyParams(key interface{}) ([]interface{}, []string
 	} else if n == 1 {
 		return tm.bindParams(tm.typ.KeyFields, []interface{}{key})
 	} else {
+		if kc, ok := key.(keyCollection); ok {
+			return tm.bindParams(tm.typ.KeyFields, kc.Keys())
+		}
 		key, ok := key.([]interface{})
 		if !ok {
 			return nil, nil, errors.New("expected key to be a slice")