MyBatis框架
5.4 set
- set 主要是用于解决修改操作中SQL语句中可能多出逗号的问题
<update id="updateEmpByConditionSet"> update tbl_employee <set> <if test="lastName!=null && lastName!="""> last_name = #{lastName}, </if> <if test="email!=null and email.trim()!=''"> email = #{email} , </if> <if test=""m".equals(gender) or "f".equals(gender)"> gender = #{gender} </if> </set> where id =#{id} </update> |
5.5 choose(when、otherwise)
- choose 主要是用于分支判断,类似于java中的switch case,只会满足所有分支中的一个
<select id="getEmpsByConditionChoose" resultType="com.atguigu.mybatis.beans.Employee"> select id ,last_name, email,gender from tbl_employee <where> <choose> <when test="id!=null"> id = #{id} </when> <when test="lastName!=null"> last_name = #{lastName} </when> <when test="email!=null"> email = #{email} </when> <otherwise> gender = 'm' </otherwise> </choose> </where> </select> |