MyBatis在注解上使用动态SQL方式(@select使用if)

@Select({"<script>",
                "SELECT * FROM tbl_order",
                "WHERE 1=1",
                "<when test='title!=null'>",
                "AND mydate = #{mydate}",
                "</when>",
                "</script>"})

public class OrderProvider {
    private final String TBL_ORDER = "tbl_order"; 
    public String queryOrderByParam(OrderPara param) {
        SQL sql = new SQL().SELECT("*").FROM(TBL_ORDER);
        String room = param.getRoom();
        if (StringUtils.hasText(room)) {
            sql.WHERE("room LIKE #{room}");
        }
        Date myDate = param.getMyDate();
        if (myDate != null) {
            sql.WHERE("mydate LIKE #{mydate}");
        }
        return sql.toString();
    }
}
 
public interface OrderDAO {    
    @SelectProvider(type = OrderProvider.class, method = "queryOrderByParam")
    List<Order> queryOrderByParam(OrderParam param); 
}

@Select("<script>SELECT ...</script>")

 <select id="slectSlagsteelRatioByDate" resultType="java.lang.Double">
 
--         select slagsteel_ratio FROM process_history WHERE r furnace_num = #{furnaceNum}
--         ORDER BY real_time DESC limit 0,1
 
select slagsteel_ratio FROM(
 select slagsteel_ratio FROM process_history WHERE real_time &lt;= #{date,jdbcType=TIMESTAMP}
 ORDER BY real_time DESC ) WHERE ROWNUM = 1
</select>

ORDER BY eeee ORDER BY rrrrrr

           CASE
           WHEN  条件1 THEN 字段1

           ELSE    字段3
           END
  FROM.....