Mybatis实现动态排序方式

SELECT 
name , sex , age , user_grade as userGrade
FROM user
<if test="orderField !=null and orderField != '' ">
    order by ${orderField}  ${orderType}
</if>

User user = new User();
//以user_grade字段排序
user.setOrderField("user_grade");
//降序
user.setOrderType("desc");
//可在User类中添加
//在未传入时，使用set注入，设置默认值
public String getOrderField() {
        if (orderField == null || "".equals(orderField)) {
            orderField = "create_time";
        }
        return orderField;
    }
    public String getOrderType() {
        if (orderType == null || "".equals(orderType)) {
            orderType = "desc";
        }
        return orderType;
    }

SELECT 
name , sex , age , user_grade as userGrade
FROM user
<if test="orderField != null" >
    ORDER BY
    <choose>
        <when test="orderField == 'name'">
            name ${orderType}
        </when>
        <when test="orderField == 'age'">
            age ${orderType}
        </when>
        <when test="orderField == 'userGrade'">
            user_grade ${orderType}
        </when>
        <otherwise>
            create_time ${orderType}
        </otherwise>
    </choose>
</if>

user.setOrderField("userGrade");

select * from  table_name order by #{field}

==> Preparing: SELECT * FROM table_name ORDER BY ?
==> Parameters: time(String）

SELECT * FROM table_name ORDER BY 'time'

select * from table_name order by time