Empty sort appended bug fix

pkg/reflection/helpers.go

@@ -1,9 +1,15 @@
-package common
+package reflection
 
 import "reflect"
 
 func Len(v any) int {
 	val := reflect.ValueOf(v)
+	valKind := val.Kind()
+
+	if valKind == reflect.Ptr {
+		val = val.Elem()
+	}
+
 	switch val.Kind() {
 	case reflect.Slice, reflect.Array, reflect.Map, reflect.String, reflect.Chan:
 		return val.Len()

pkg/resolvespec/handler.go

@@ -200,7 +200,7 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 	if len(options.ComputedColumns) > 0 {
 		for _, cu := range options.ComputedColumns {
 			logger.Debug("Applying computed column: %s", cu.Name)
-			query = query.ColumnExpr("(?) AS "+cu.Name, cu.Expression)
+			query = query.ColumnExpr(fmt.Sprintf("(%s) AS %s", cu.Expression, cu.Name))
 		}
 	}
 

pkg/restheadspec/handler.go

@@ -257,7 +257,7 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 	if len(options.ComputedQL) > 0 {
 		for colName, colExpr := range options.ComputedQL {
 			logger.Debug("Applying computed column: %s", colName)
-			query = query.ColumnExpr("(?) AS "+colName, colExpr)
+			query = query.ColumnExpr(fmt.Sprintf("(%s) AS %s", colExpr, colName))
 			for colIndex := range options.Columns {
 				if options.Columns[colIndex] == colName {
 					// Remove the computed column from the selected columns to avoid duplication
@@ -271,7 +271,7 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 	if len(options.ComputedColumns) > 0 {
 		for _, cu := range options.ComputedColumns {
 			logger.Debug("Applying computed column: %s", cu.Name)
-			query = query.ColumnExpr("(?) AS "+cu.Name, cu.Expression)
+			query = query.ColumnExpr(fmt.Sprintf("(%s) AS %s", cu.Expression, cu.Name))
 			for colIndex := range options.Columns {
 				if options.Columns[colIndex] == cu.Name {
 					// Remove the computed column from the selected columns to avoid duplication
@@ -293,6 +293,9 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 		logger.Debug("Applying expand: %s", expand.Relation)
 		sorts := make([]common.SortOption, 0)
 		for _, s := range strings.Split(expand.Sort, ",") {
+			if s == "" {
+				continue
+			}
 			dir := "ASC"
 			if strings.HasPrefix(s, "-") || strings.HasSuffix(strings.ToUpper(s), " DESC") {
 				dir = "DESC"
@@ -523,7 +526,7 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 
 	metadata := &common.Metadata{
 		Total:    int64(total),
-		Count:    int64(common.Len(modelPtr)),
+		Count:    int64(reflection.Len(modelPtr)),
 		Filtered: int64(total),
 		Limit:    limit,
 		Offset:   offset,
@@ -1531,6 +1534,9 @@ func (h *Handler) FetchRowNumber(ctx context.Context, tableName string, pkName s
 	if len(options.Sort) > 0 {
 		sortParts := make([]string, 0, len(options.Sort))
 		for _, sort := range options.Sort {
+			if sort.Column == "" {
+				continue
+			}
 			direction := "ASC"
 			if strings.EqualFold(sort.Direction, "desc") {
 				direction = "DESC"

pkg/restheadspec/headers.go

@@ -146,7 +146,12 @@ func (h *Handler) parseOptionsFromHeaders(r common.Request) ExtendedRequestOptio
 
 		// Joins & Relations
 		case strings.HasPrefix(normalizedKey, "x-preload"):
-			h.parsePreload(&options, decodedValue)
+			if strings.HasSuffix(normalizedKey, "-where") {
+				continue
+			}
+			whereClaude := headers[fmt.Sprintf("%s-where", key)]
+			h.parsePreload(&options, decodedValue, decodeHeaderValue(whereClaude))
+
 		case strings.HasPrefix(normalizedKey, "x-expand"):
 			h.parseExpand(&options, decodedValue)
 		case strings.HasPrefix(normalizedKey, "x-custom-sql-join"):
@@ -341,7 +346,15 @@ func (h *Handler) mapSearchOperator(colName, operator, value string) common.Filt
 
 // parsePreload parses x-preload header
 // Format: RelationName:field1,field2 or RelationName or multiple separated by |
-func (h *Handler) parsePreload(options *ExtendedRequestOptions, value string) {
+func (h *Handler) parsePreload(options *ExtendedRequestOptions, values ...string) {
+	if len(values) == 0 {
+		return
+	}
+	value := values[0]
+	whereClause := ""
+	if len(values) > 1 {
+		whereClause = values[1]
+	}
 	if value == "" {
 		return
 	}
@@ -358,6 +371,7 @@ func (h *Handler) parsePreload(options *ExtendedRequestOptions, value string) {
 		parts := strings.SplitN(preloadStr, ":", 2)
 		preload := common.PreloadOption{
 			Relation: strings.TrimSpace(parts[0]),
+			Where:    whereClause,
 		}
 
 		if len(parts) == 2 {