Fixed order by. Added OrderExpr to database interface

pkg/common/adapters/database/bun.go

@@ -691,6 +691,11 @@ func (b *BunSelectQuery) Order(order string) common.SelectQuery {
 	return b
 }
 
+func (b *BunSelectQuery) OrderExpr(order string, args ...interface{}) common.SelectQuery {
+	b.query = b.query.OrderExpr(order, args...)
+	return b
+}
+
 func (b *BunSelectQuery) Limit(n int) common.SelectQuery {
 	b.query = b.query.Limit(n)
 	return b

pkg/common/adapters/database/gorm.go

@@ -386,6 +386,12 @@ func (g *GormSelectQuery) Order(order string) common.SelectQuery {
 	return g
 }
 
+func (g *GormSelectQuery) OrderExpr(order string, args ...interface{}) common.SelectQuery {
+	// GORM's Order can handle expressions directly
+	g.db = g.db.Order(gorm.Expr(order, args...))
+	return g
+}
+
 func (g *GormSelectQuery) Limit(n int) common.SelectQuery {
 	g.db = g.db.Limit(n)
 	return g

pkg/common/adapters/database/pgsql.go

@@ -281,6 +281,13 @@ func (p *PgSQLSelectQuery) Order(order string) common.SelectQuery {
 	return p
 }
 
+func (p *PgSQLSelectQuery) OrderExpr(order string, args ...interface{}) common.SelectQuery {
+	// For PgSQL, expressions are passed directly without quoting
+	// If there are args, we would need to format them, but for now just append the expression
+	p.orderBy = append(p.orderBy, order)
+	return p
+}
+
 func (p *PgSQLSelectQuery) Limit(n int) common.SelectQuery {
 	p.limit = n
 	return p

pkg/common/interfaces.go

@@ -46,6 +46,7 @@ type SelectQuery interface {
 	PreloadRelation(relation string, apply ...func(SelectQuery) SelectQuery) SelectQuery
 	JoinRelation(relation string, apply ...func(SelectQuery) SelectQuery) SelectQuery
 	Order(order string) SelectQuery
+	OrderExpr(order string, args ...interface{}) SelectQuery
 	Limit(n int) SelectQuery
 	Offset(n int) SelectQuery
 	Group(group string) SelectQuery

pkg/common/validation.go

@@ -237,6 +237,13 @@ func (v *ColumnValidator) FilterRequestOptions(options RequestOptions) RequestOp
 	for _, sort := range options.Sort {
 		if v.IsValidColumn(sort.Column) {
 			validSorts = append(validSorts, sort)
+		} else if strings.HasPrefix(sort.Column, "(") && strings.HasSuffix(sort.Column, ")") {
+			// Allow sort by expression/subquery, but validate for security
+			if IsSafeSortExpression(sort.Column) {
+				validSorts = append(validSorts, sort)
+			} else {
+				logger.Warn("Unsafe sort expression '%s' removed", sort.Column)
+			}
 		} else {
 			logger.Warn("Invalid column in sort '%s' removed", sort.Column)
 		}
@@ -262,6 +269,24 @@ func (v *ColumnValidator) FilterRequestOptions(options RequestOptions) RequestOp
 		}
 		filteredPreload.Filters = validPreloadFilters
 
+		// Filter preload sort columns
+		validPreloadSorts := make([]SortOption, 0, len(preload.Sort))
+		for _, sort := range preload.Sort {
+			if v.IsValidColumn(sort.Column) {
+				validPreloadSorts = append(validPreloadSorts, sort)
+			} else if strings.HasPrefix(sort.Column, "(") && strings.HasSuffix(sort.Column, ")") {
+				// Allow sort by expression/subquery, but validate for security
+				if IsSafeSortExpression(sort.Column) {
+					validPreloadSorts = append(validPreloadSorts, sort)
+				} else {
+					logger.Warn("Unsafe sort expression in preload '%s' removed: '%s'", preload.Relation, sort.Column)
+				}
+			} else {
+				logger.Warn("Invalid column in preload '%s' sort '%s' removed", preload.Relation, sort.Column)
+			}
+		}
+		filteredPreload.Sort = validPreloadSorts
+
 		validPreloads = append(validPreloads, filteredPreload)
 	}
 	filtered.Preload = validPreloads
@@ -269,6 +294,56 @@ func (v *ColumnValidator) FilterRequestOptions(options RequestOptions) RequestOp
 	return filtered
 }
 
+// IsSafeSortExpression validates that a sort expression (enclosed in brackets) is safe
+// and doesn't contain SQL injection attempts or dangerous commands
+func IsSafeSortExpression(expr string) bool {
+	if expr == "" {
+		return false
+	}
+
+	// Expression must be enclosed in brackets
+	expr = strings.TrimSpace(expr)
+	if !strings.HasPrefix(expr, "(") || !strings.HasSuffix(expr, ")") {
+		return false
+	}
+
+	// Remove outer brackets for content validation
+	expr = expr[1 : len(expr)-1]
+	expr = strings.TrimSpace(expr)
+
+	// Convert to lowercase for checking dangerous keywords
+	exprLower := strings.ToLower(expr)
+
+	// Check for dangerous SQL commands that should never be in a sort expression
+	dangerousKeywords := []string{
+		"drop ", "delete ", "insert ", "update ", "alter ", "create ",
+		"truncate ", "exec ", "execute ", "grant ", "revoke ",
+		"into ", "values ", "set ", "shutdown", "xp_",
+	}
+
+	for _, keyword := range dangerousKeywords {
+		if strings.Contains(exprLower, keyword) {
+			logger.Warn("Dangerous SQL keyword '%s' detected in sort expression: %s", keyword, expr)
+			return false
+		}
+	}
+
+	// Check for SQL comment attempts
+	if strings.Contains(expr, "--") || strings.Contains(expr, "/*") || strings.Contains(expr, "*/") {
+		logger.Warn("SQL comment detected in sort expression: %s", expr)
+		return false
+	}
+
+	// Check for semicolon (command separator)
+	if strings.Contains(expr, ";") {
+		logger.Warn("Command separator (;) detected in sort expression: %s", expr)
+		return false
+	}
+
+	// Expression appears safe
+	return true
+}
+
 // GetValidColumns returns a list of all valid column names for debugging purposes
 func (v *ColumnValidator) GetValidColumns() []string {
 	columns := make([]string, 0, len(v.validColumns))

pkg/common/validation_test.go

@@ -361,3 +361,83 @@ func TestFilterRequestOptions(t *testing.T) {
 		t.Errorf("Expected sort column 'id', got %s", filtered.Sort[0].Column)
 	}
 }
+
+func TestIsSafeSortExpression(t *testing.T) {
+	tests := []struct {
+		name       string
+		expression string
+		shouldPass bool
+	}{
+		// Safe expressions
+		{"Valid subquery", "(SELECT MAX(price) FROM products)", true},
+		{"Valid CASE expression", "(CASE WHEN status = 'active' THEN 1 ELSE 0 END)", true},
+		{"Valid aggregate", "(COUNT(*) OVER (PARTITION BY category))", true},
+		{"Valid function", "(COALESCE(discount, 0))", true},
+
+		// Dangerous expressions - SQL injection attempts
+		{"DROP TABLE attempt", "(id); DROP TABLE users; --", false},
+		{"DELETE attempt", "(id WHERE 1=1); DELETE FROM users; --", false},
+		{"INSERT attempt", "(id); INSERT INTO admin VALUES ('hacker'); --", false},
+		{"UPDATE attempt", "(id); UPDATE users SET role='admin'; --", false},
+		{"EXEC attempt", "(id); EXEC sp_executesql 'DROP TABLE users'; --", false},
+		{"XP_ stored proc", "(id); xp_cmdshell 'dir'; --", false},
+
+		// Comment injection
+		{"SQL comment dash", "(id) -- malicious comment", false},
+		{"SQL comment block start", "(id) /* comment", false},
+		{"SQL comment block end", "(id) comment */", false},
+
+		// Semicolon attempts
+		{"Semicolon separator", "(id); SELECT * FROM passwords", false},
+
+		// Empty/invalid
+		{"Empty string", "", false},
+		{"Just brackets", "()", true}, // Empty but technically valid structure
+		{"No brackets", "id", false},  // Must have brackets for expressions
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := IsSafeSortExpression(tt.expression)
+			if result != tt.shouldPass {
+				t.Errorf("IsSafeSortExpression(%q) = %v, want %v", tt.expression, result, tt.shouldPass)
+			}
+		})
+	}
+}
+
+func TestFilterRequestOptions_WithSortExpressions(t *testing.T) {
+	model := TestModel{}
+	validator := NewColumnValidator(model)
+
+	options := RequestOptions{
+		Sort: []SortOption{
+			{Column: "id", Direction: "ASC"},                                    // Valid column
+			{Column: "(SELECT MAX(age) FROM users)", Direction: "DESC"},         // Safe expression
+			{Column: "name", Direction: "ASC"},                                  // Valid column
+			{Column: "(id); DROP TABLE users; --", Direction: "DESC"},          // Dangerous expression
+			{Column: "invalid_col", Direction: "ASC"},                           // Invalid column
+			{Column: "(CASE WHEN age > 18 THEN 1 ELSE 0 END)", Direction: "ASC"}, // Safe expression
+		},
+	}
+
+	filtered := validator.FilterRequestOptions(options)
+
+	// Should keep: id, safe expression, name, another safe expression
+	// Should remove: dangerous expression, invalid column
+	expectedCount := 4
+	if len(filtered.Sort) != expectedCount {
+		t.Errorf("Expected %d sort options, got %d", expectedCount, len(filtered.Sort))
+	}
+
+	// Verify the kept options
+	if filtered.Sort[0].Column != "id" {
+		t.Errorf("Expected first sort to be 'id', got '%s'", filtered.Sort[0].Column)
+	}
+	if filtered.Sort[1].Column != "(SELECT MAX(age) FROM users)" {
+		t.Errorf("Expected second sort to be safe expression, got '%s'", filtered.Sort[1].Column)
+	}
+	if filtered.Sort[2].Column != "name" {
+		t.Errorf("Expected third sort to be 'name', got '%s'", filtered.Sort[2].Column)
+	}
+}

pkg/restheadspec/handler.go

@@ -513,7 +513,15 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 			direction = "DESC"
 		}
 		logger.Debug("Applying sort: %s %s", sort.Column, direction)
-		query = query.Order(fmt.Sprintf("%s %s", sort.Column, direction))
+
+		// Check if it's an expression (enclosed in brackets) - use directly without quoting
+		if strings.HasPrefix(sort.Column, "(") && strings.HasSuffix(sort.Column, ")") {
+			// For expressions, pass as raw SQL to prevent auto-quoting
+			query = query.OrderExpr(fmt.Sprintf("%s %s", sort.Column, direction))
+		} else {
+			// Regular column - let Bun handle quoting
+			query = query.Order(fmt.Sprintf("%s %s", sort.Column, direction))
+		}
 	}
 
 	// Get total count before pagination (unless skip count is requested)
@@ -827,7 +835,14 @@ func (h *Handler) applyPreloadWithRecursion(query common.SelectQuery, preload co
 		// Apply sorting
 		if len(preload.Sort) > 0 {
 			for _, sort := range preload.Sort {
-				sq = sq.Order(fmt.Sprintf("%s %s", sort.Column, sort.Direction))
+				// Check if it's an expression (enclosed in brackets) - use directly without quoting
+				if strings.HasPrefix(sort.Column, "(") && strings.HasSuffix(sort.Column, ")") {
+					// For expressions, pass as raw SQL to prevent auto-quoting
+					sq = sq.OrderExpr(fmt.Sprintf("%s %s", sort.Column, sort.Direction))
+				} else {
+					// Regular column - let ORM handle quoting
+					sq = sq.Order(fmt.Sprintf("%s %s", sort.Column, sort.Direction))
+				}
 			}
 		}
 
@@ -2188,7 +2203,14 @@ func (h *Handler) FetchRowNumber(ctx context.Context, tableName string, pkName s
 			if strings.EqualFold(sort.Direction, "desc") {
 				direction = "DESC"
 			}
-			sortParts = append(sortParts, fmt.Sprintf("%s.%s %s", tableName, sort.Column, direction))
+
+			// Check if it's an expression (enclosed in brackets) - use directly without table prefix
+			if strings.HasPrefix(sort.Column, "(") && strings.HasSuffix(sort.Column, ")") {
+				sortParts = append(sortParts, fmt.Sprintf("%s %s", sort.Column, direction))
+			} else {
+				// Regular column - add table prefix
+				sortParts = append(sortParts, fmt.Sprintf("%s.%s %s", tableName, sort.Column, direction))
+			}
 		}
 		sortSQL = strings.Join(sortParts, ", ")
 	} else {
@@ -2397,6 +2419,55 @@ func (h *Handler) filterExtendedOptions(validator *common.ColumnValidator, optio
 			expandValidator := common.NewColumnValidator(relInfo.relatedModel)
 			// Filter columns using the related model's validator
 			filteredExpand.Columns = expandValidator.FilterValidColumns(expand.Columns)
+
+			// Filter sort columns in the expand Sort string
+			if expand.Sort != "" {
+				sortFields := strings.Split(expand.Sort, ",")
+				validSortFields := make([]string, 0, len(sortFields))
+				for _, sortField := range sortFields {
+					sortField = strings.TrimSpace(sortField)
+					if sortField == "" {
+						continue
+					}
+
+					// Extract column name (remove direction prefixes/suffixes)
+					colName := sortField
+					direction := ""
+
+					if strings.HasPrefix(sortField, "-") {
+						direction = "-"
+						colName = strings.TrimPrefix(sortField, "-")
+					} else if strings.HasPrefix(sortField, "+") {
+						direction = "+"
+						colName = strings.TrimPrefix(sortField, "+")
+					}
+
+					if strings.HasSuffix(strings.ToLower(colName), " desc") {
+						direction = " desc"
+						colName = strings.TrimSuffix(strings.ToLower(colName), " desc")
+					} else if strings.HasSuffix(strings.ToLower(colName), " asc") {
+						direction = " asc"
+						colName = strings.TrimSuffix(strings.ToLower(colName), " asc")
+					}
+
+					colName = strings.TrimSpace(colName)
+
+					// Validate the column name
+					if expandValidator.IsValidColumn(colName) {
+						validSortFields = append(validSortFields, direction+colName)
+					} else if strings.HasPrefix(colName, "(") && strings.HasSuffix(colName, ")") {
+						// Allow sort by expression/subquery, but validate for security
+						if common.IsSafeSortExpression(colName) {
+							validSortFields = append(validSortFields, direction+colName)
+						} else {
+							logger.Warn("Unsafe sort expression in expand '%s' removed: '%s'", expand.Relation, colName)
+						}
+					} else {
+						logger.Warn("Invalid column in expand '%s' sort '%s' removed", expand.Relation, colName)
+					}
+				}
+				filteredExpand.Sort = strings.Join(validSortFields, ",")
+			}
 		} else {
 			// If we can't find the relationship, log a warning and skip column filtering
 			logger.Warn("Cannot validate columns for unknown relation: %s", expand.Relation)

pkg/restheadspec/headers.go

@@ -529,19 +529,47 @@ func (h *Handler) parseSorting(options *ExtendedRequestOptions, value string) {
 }
 
 // parseCommaSeparated parses comma-separated values and trims whitespace
+// It respects bracket nesting and only splits on commas outside of parentheses
 func (h *Handler) parseCommaSeparated(value string) []string {
 	if value == "" {
 		return nil
 	}
 
-	parts := strings.Split(value, ",")
-	result := make([]string, 0, len(parts))
-	for _, part := range parts {
-		part = strings.TrimSpace(part)
-		if part != "" {
-			result = append(result, part)
+	result := make([]string, 0)
+	var current strings.Builder
+	nestingLevel := 0
+
+	for _, char := range value {
+		switch char {
+		case '(':
+			nestingLevel++
+			current.WriteRune(char)
+		case ')':
+			nestingLevel--
+			current.WriteRune(char)
+		case ',':
+			if nestingLevel == 0 {
+				// We're outside all brackets, so split here
+				part := strings.TrimSpace(current.String())
+				if part != "" {
+					result = append(result, part)
+				}
+				current.Reset()
+			} else {
+				// Inside brackets, keep the comma
+				current.WriteRune(char)
+			}
+		default:
+			current.WriteRune(char)
 		}
 	}
+
+	// Add the last part
+	part := strings.TrimSpace(current.String())
+	if part != "" {
+		result = append(result, part)
+	}
+
 	return result
 }