CREATE TABLE `user` (
  `id` bigint(20) NOT NULL COMMENT '主鍵',
  `name` varchar(12)  COMMENT '用戶名稱',
  `hobby` varchar(12) DEFAULT NULL COMMENT '愛好',
  `age`  int(11) DEFAULT NULL COMMENT '用戶年齡',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 ROW_FORMAT=DYNAMIC COMMENT='用戶表';

import lombok.Data;
@Data
public class UserVO extends User {
	/**
	 * 操作運(yùn)算符:>=/<=/=
	 */
    private String operateStr;
}

    <select id="selectUsers" resultType="org.springboot.xg.vo.UserVO">
        select * from user
        <where>
            <if test="userVO.operateStr!= null and userVO.operateStr != '' and  userVO.age!= null">
                and avg_delay ${userVO.operateStr} #{userVO.age}
            </if>
        </where>
    </select>

package org.springboot.xg.enums;
import lombok.AllArgsConstructor;
import lombok.Getter;
@Getter
@AllArgsConstructor
public enum OperateEnum {
	// 大于等于
	GREATER_THAN_OR_EQUAL_TO(1, ">="),
	// 等于
	BE_EQUAL_TO(2, "="),
	// 小于等于
	LESS_THAN_OR_EQUAL_TO(3, "<=");
	/**
	 * 操作符對(duì)應(yīng)整數(shù)值
	 */
	private final Integer operateIntValue;
	/**
	 * 條件
	 */
	private final String condition;
	/**
	 * 根據(jù)值獲取條件
	 *
	 * @param value 值
	 * @return 條件
	 */
	public static String getConditionByIntValue(Integer value) {
		for (OperateEnum item : OperateEnum.values()) {
			if (item.getOperateIntValue().equals(value)) {
				return item.getCondition();
			}
		}
		return null;
	}
}