feat: query_parser + stringcase.

query_parser/orderby.go

@@ -0,0 +1,50 @@
+package query_parser
+
+import (
+	"strings"
+)
+
+type OrderByHandler func(field string, desc bool)
+
+// ParseOrderByString 解析排序字符串，调用处理函数。
+func ParseOrderByString(orderBy string, handler OrderByHandler) error {
+	if orderBy == "" {
+		return nil
+	}
+
+	parts := strings.Split(orderBy, ",")
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		ParseOrderByField(part, handler)
+	}
+
+	return nil
+}
+
+// ParseOrderByStrings 解析多个排序字符串，调用处理函数。
+func ParseOrderByStrings(orderBys []string, handler OrderByHandler) error {
+	for _, v := range orderBys {
+		if v == "" {
+			continue
+		}
+
+		ParseOrderByField(v, handler)
+	}
+	return nil
+}
+
+// ParseOrderByField 解析单个排序字段，调用处理函数。
+func ParseOrderByField(orderBy string, handler OrderByHandler) {
+	orderBy = strings.TrimSpace(orderBy)
+	if orderBy == "" {
+		return // 没有排序条件
+	}
+
+	if strings.HasPrefix(orderBy, "-") {
+		handler(orderBy[1:], true) // 降序
+	} else if strings.HasPrefix(orderBy, "+") {
+		handler(orderBy[1:], false) // 升序
+	} else {
+		handler(orderBy, false) // 升序
+	}
+}