mybatis实现saveorupdate

<insert id="saveOrUpdate" >
    <selectKey keyProperty="count" resultType="int" order="BEFORE">
        select count(*) from user where email = #{email}
    </selectKey>
    <if test="count > 0">
        update user
        set auth_code = #{authCode}
        where email = #{email}
    </if>
    <if test="count==0">
        INSERT INTO user(email, auth_code, count)
        VALUE (#{email},#{authCode},#{count})
    </if>
</insert>