feat(reflection): add IsEmptyValue helper; guard CUD ops against missing PK

Add reflection.IsEmptyValue to detect nil, empty string, and zero numbers.
Use it in recursive CUD processing to skip update/delete when the primary
key is absent, logging a warning instead of proceeding with an invalid operation.

pkg/common/adapters/database/bun.go

@@ -289,19 +289,20 @@ func (b *BunAdapter) DriverName() string {
 
 // BunSelectQuery implements SelectQuery for Bun
 type BunSelectQuery struct {
-	query          *bun.SelectQuery
-	db             bun.IDB // Store DB connection for count queries
-	hasModel       bool    // Track if Model() was called
-	schema         string  // Separated schema name
-	tableName      string  // Just the table name, without schema
-	entity         string
-	tableAlias     string
-	driverName     string                                                   // Database driver name (postgres, sqlite, mssql)
-	inJoinContext  bool                                                     // Track if we're in a JOIN relation context
-	joinTableAlias string                                                   // Alias to use for JOIN conditions
-	skipAutoDetect bool                                                     // Skip auto-detection to prevent circular calls
-	customPreloads map[string][]func(common.SelectQuery) common.SelectQuery // Relations to load with custom implementation
-	metricsEnabled bool
+	query                *bun.SelectQuery
+	db                   bun.IDB // Store DB connection for count queries
+	hasModel             bool    // Track if Model() was called
+	schema               string  // Separated schema name
+	tableName            string  // Just the table name, without schema
+	entity               string
+	tableAlias           string
+	driverName           string                                                   // Database driver name (postgres, sqlite, mssql)
+	inJoinContext        bool                                                     // Track if we're in a JOIN relation context
+	joinTableAlias       string                                                   // Alias to use for JOIN conditions
+	skipAutoDetect       bool                                                     // Skip auto-detection to prevent circular calls
+	preloadRelationAlias string                                                   // Relation alias used in separate-query preloads (e.g. "tprp" for relation "TPRP")
+	customPreloads       map[string][]func(common.SelectQuery) common.SelectQuery // Relations to load with custom implementation
+	metricsEnabled       bool
 }
 
 func (b *BunSelectQuery) Model(model interface{}) common.SelectQuery {
@@ -346,12 +347,14 @@ func (b *BunSelectQuery) ColumnExpr(query string, args ...interface{}) common.Se
 }
 
 func (b *BunSelectQuery) Where(query string, args ...interface{}) common.SelectQuery {
-	// If we're in a JOIN context, add table prefix to unqualified columns
 	if b.inJoinContext && b.joinTableAlias != "" {
 		query = addTablePrefix(query, b.joinTableAlias)
+	} else if b.preloadRelationAlias != "" && b.tableName != "" {
+		// Separate-query preload: the caller may have written conditions using the
+		// relation name as a prefix (e.g. "TPRP.col"). Bun uses the real table name
+		// as the alias, so rewrite any such references to use tableName instead.
+		query = replaceRelationAlias(query, b.preloadRelationAlias, b.tableName)
 	} else if b.tableAlias != "" && b.tableName != "" {
-		// If we have a table alias defined, check if the query references a different alias
-		// This can happen in preloads where the user expects a certain alias but Bun generates another
 		query = normalizeTableAlias(query, b.tableAlias, b.tableName)
 	}
 	b.query = b.query.Where(query, args...)
@@ -487,6 +490,30 @@ func normalizeTableAlias(query, expectedAlias, tableName string) string {
 	return modified
 }
 
+// replaceRelationAlias rewrites WHERE conditions written with a relation alias prefix
+// (e.g. "TPRP.col") to use the real table name that bun uses in separate queries
+// (e.g. "t_proposalinstance.col"). Only called for separate-query preload wrappers.
+func replaceRelationAlias(query, relationAlias, tableName string) string {
+	if relationAlias == "" || tableName == "" || query == "" {
+		return query
+	}
+	parts := strings.FieldsFunc(query, func(r rune) bool {
+		return r == ' ' || r == '(' || r == ')' || r == ','
+	})
+	modified := query
+	for _, part := range parts {
+		if dotIndex := strings.Index(part, "."); dotIndex > 0 {
+			prefix := part[:dotIndex]
+			column := part[dotIndex+1:]
+			if strings.EqualFold(prefix, relationAlias) {
+				logger.Debug("Replacing relation alias '%s' with table name '%s' in preload WHERE condition", prefix, tableName)
+				modified = strings.ReplaceAll(modified, part, tableName+"."+column)
+			}
+		}
+	}
+	return modified
+}
+
 func isJoinKeyword(word string) bool {
 	switch strings.ToUpper(word) {
 	case "JOIN", "INNER", "LEFT", "RIGHT", "FULL", "OUTER", "CROSS":
@@ -676,8 +703,20 @@ func (b *BunSelectQuery) PreloadRelation(relation string, apply ...func(common.S
 				wrapper.tableAlias = provider.TableAlias()
 				logger.Debug("Preload relation '%s' using table alias: %s", relation, wrapper.tableAlias)
 			}
+
 		}
 
+		// Fallback: if the model didn't provide a table name, ask bun directly.
+		if wrapper.tableName == "" {
+			wrapper.schema, wrapper.tableName = parseTableName(sq.GetTableName(), b.driverName)
+		}
+
+		// For separate-query preloads (has-many), bun aliases the related table using
+		// the actual table name, not the relation name. Record the relation alias so
+		// Where() can rewrite conditions like "TPRP.col" to "t_proposalinstance.col".
+		wrapper.preloadRelationAlias = strings.ToLower(relation)
+		logger.Debug("Preload relation '%s' registered alias '%s' for separate-query WHERE rewriting", relation, wrapper.preloadRelationAlias)
+
 		// Start with the interface value (not pointer)
 		current := common.SelectQuery(wrapper)
 

pkg/common/recursive_crud.go

@@ -141,8 +141,12 @@ func (p *NestedCUDProcessor) ProcessNestedCUD(
 			logger.Debug("Skipping insert for %s - no data columns besides _request", tableName)
 		}
 
-	case "update":
+	case "update", "change":
 		// Only perform update if we have data to update
+		if reflection.IsEmptyValue(data[pkName]) {
+			logger.Warn("Skipping update for %s - no primary key", tableName)
+			return result, nil
+		}
 		if hasData {
 			rows, err := p.processUpdate(ctx, regularData, tableName, data[pkName])
 			if err != nil {
@@ -171,10 +175,15 @@ func (p *NestedCUDProcessor) ProcessNestedCUD(
 		}
 
 	case "delete":
+		if reflection.IsEmptyValue(data[pkName]) {
+			logger.Warn("Skipping delete for %s - no primary key", tableName)
+			return result, nil
+		}
+
 		// Process child relations first (for referential integrity)
 		if err := p.processChildRelations(ctx, "delete", data[pkName], relationFields, result.RelationData, modelType, parentIDs); err != nil {
 			logger.Error("Failed to process child relations before delete: table=%s, id=%v, relations=%+v, error=%v", tableName, data[pkName], relationFields, err)
-			return nil, nil
+			return nil, fmt.Errorf("failed to process child relations: %w", err)
 		}
 
 		rows, err := p.processDelete(ctx, tableName, data[pkName])

pkg/reflection/helpers.go

@@ -51,6 +51,31 @@ func ExtractTableNameOnly(fullName string) string {
 	return fullName[startIndex:]
 }
 
+// IsEmptyValue reports whether v is nil, an empty string, or a zero number.
+func IsEmptyValue(v any) bool {
+	if v == nil {
+		return true
+	}
+	rv := reflect.ValueOf(v)
+	if rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			return true
+		}
+		rv = rv.Elem()
+	}
+	switch rv.Kind() {
+	case reflect.String:
+		return rv.String() == ""
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return rv.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return rv.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return rv.Float() == 0
+	}
+	return false
+}
+
 // GetPointerElement returns the element type if the provided reflect.Type is a pointer.
 // If the type is a slice of pointers, it returns the element type of the pointer within the slice.
 // If neither condition is met, it returns the original type.

pkg/restheadspec/empty_result_test.go

@@ -14,23 +14,23 @@ func TestNormalizeResultArray_EmptyArrayWhenNoID(t *testing.T) {
 	handler := &Handler{}
 
 	tests := []struct {
-		name            string
-		input           interface{}
+		name             string
+		input            interface{}
 		shouldBeEmptyObj bool
 	}{
 		{
-			name:            "nil should return empty object",
-			input:           nil,
+			name:             "nil should return empty object",
+			input:            nil,
 			shouldBeEmptyObj: true,
 		},
 		{
-			name:            "empty slice should return empty object",
-			input:           []*EmptyTestModel{},
+			name:             "empty slice should return empty object",
+			input:            []*EmptyTestModel{},
 			shouldBeEmptyObj: true,
 		},
 		{
-			name:            "single element should return the element",
-			input:           []*EmptyTestModel{{ID: 1, Name: "test"}},
+			name:             "single element should return the element",
+			input:            []*EmptyTestModel{{ID: 1, Name: "test"}},
 			shouldBeEmptyObj: false,
 		},
 		{
@@ -138,9 +138,9 @@ func TestSendResponseWithOptions_NoDataFoundHeader(t *testing.T) {
 		t.Errorf("Expected X-No-Data-Found header to be 'true', got '%s'", mockWriter.headers["X-No-Data-Found"])
 	}
 
-	// Check status code is 204 when no records found
-	if mockWriter.statusCode != 204 {
-		t.Errorf("Expected status code 204, got %d", mockWriter.statusCode)
+	// Check status code is 200 even when no records found
+	if mockWriter.statusCode != 200 {
+		t.Errorf("Expected status code 200, got %d", mockWriter.statusCode)
 	}
 
 	// Verify the body is an empty array (list request, SingleRecordAsObject not set)

pkg/restheadspec/handler.go

@@ -2507,11 +2507,7 @@ func (h *Handler) sendResponseWithOptions(w common.ResponseWriter, data interfac
 		data = h.normalizeResultArray(data)
 	}
 
-	if dataLen == 0 {
-		w.WriteHeader(http.StatusNoContent)
-	} else {
-		w.WriteHeader(http.StatusOK)
-	}
+	w.WriteHeader(http.StatusOK)
 
 	if err := w.WriteJSON(data); err != nil {
 		logger.Error("Failed to write JSON response: %v", err)