mysql convert string to number

MySQL string +0 can be converted to a number:

<!--Find whether the version satisfies the interval-->
    <select id="isVersion"  resultType="java.lang.String" parameterType="map">
        SELECT version_id  from job_release_version
        where src_version+0<=#{version}+0 and tgt_version+0>=#{version}+0
        and  job_id=#{jobId}
        limit 1
    </select>