#{index}DAO层函数方法
Public User selectUser(String name, String area);
Mapper.xml中SQL
<select id="selectUser" resultMap="BaseResultMap"> select * from user_user_t where user_name = #{0} and user_area=#{1} </select>
DAO层函数方法
Public User selectUser(Map<String, Object> map);
Mapper.xml中SQL
<select id="selectUser" resultMap="BaseResultMap"> select * from user_user_t where user_name = #{username, jdbcType=VARCHAR} and user_area = #{userarea, jdbcType=VARCHAR} </select>
Service层函数调用
public User selectUser() {
Map<String, Object> map = new HashMap<String, Object>();
map.put("username", "zhangsan");
map.put("userarea", "beijing");
User user = mapper.selectUser(map);
}
DAO层函数
public User selectUser(@Param("userName")String username, @Param("userArea")String userarea);
Mapper.xml中SQL
<select id="selectUser" resultMap="BaseResultMap"> select * from user_user_t where 1 = 1 and user_name = #{userName} and user_area=#{userArea} </select>
原文：https://www.cnblogs.com/zhaohuichn/p/9606115.html