mybatis的动态SQL

UserMapper.xml:


<!-- 1.测试多条件 -->
<select id="getUsers" resultMap="userMap">
select * from user
<where>
<if test="userName!=null">
and username = #{userName}
</if>
<if test="userAge!=0">
or userage = #{userAge}
</if>
</where>
</select>

<!-- 测试trim自定义格式 -->
<insert id="saveUser" parameterType="User">
insert into User
<!-- 自定义要添加的列格式 -->
<trim prefix="(" suffix=")" prefixOverrides=",">
<if test="id!=null">
id,
</if>
<if test="userName!=null">
username,
</if>
<if test="userAge!=0">
userage,
</if>
<if test="userAddress!=null">
useraddress
</if>
</trim>
<!-- 自定义要添加的列的值格式 -->
<trim prefix="values(" suffix=")" suffixOverrides=",">
<if test="id!=null">
#{id},
</if>
<if test="userName!=null">
#{userName},
</if>
<if test="userAge!=0">
#{userAge},
</if>
<if test="userAddress!=null">
#{userAddress}
</if>
</trim>
</insert>