mybatis中#{}和${}的区别于用法

区别:

#{},用于传递参数,相当于一个占位符,可以防止sql注入,安全;

${},用于sql的拼接,常用语group by,order by等不能使用占位符的语句中;

用法:

#{}

 "condition.userId != null and condition.userId != ''">
     AND user_id = #{condition.userId  ,jdbcType=VARCHAR}

${}

 "get" parameterType="java.util.Map" resultMap="test">
   SELECT
     "sql_column_list" />
   FROM test
   "WHERE" prefixOverrides="AND">
     "sql_condition" />

   "orderBy != null">
     ORDER BY ${orderBy}

   LIMIT 1