Mybatis <if>标签
格式:<if test=""> sql语句 </if>
<select id="selectByName" resultType="Person" parameterType="java.lang.String" >
select * from person
<if test="_parameter != null">
where name = #{name}
</if>
</select>
注意:Mybatis动态SQL单一基础类型参数用if标签时,test中应该用 _parameter
如果是类变量
<select id="selectByName" resultType="Person" parameterType="Person" >
select * from person
<where>
<if test="age!=0">
age=#{age}
</if>
<if test="gender!=null">
and gender=#{gender}
</if>
</where>
</select>