fix(sip): 修复生成订单编码异常问题

- 优化了 selectMaxOrderCode 查询，使用动态长度计算订单编码的起始位置
- 提高了代码的灵活性和鲁棒性，避免了固定长度带来的潜在问题

ruoyi-sip/src/main/resources/mapper/sip/ProjectOrderInfoMapper.xml

@@ -95,12 +95,10 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         )
     </select>
     <select id="selectMaxOrderCode" resultType="java.lang.Integer">
-        select ifnull( max(SUBSTR( order_code FROM 16 FOR 3 )), 0 )
+        select ifnull( max(SUBSTR( order_code FROM LENGTH(#{province})+1 FOR 3 )), 0 )
         from project_order_info
         where order_code like concat(#{province}, '%')
 
-
-
     </select>
     <select id="selectAgentProvinceByProjectId" resultType="java.lang.String">
         select t2.province