XML中SQL的if标签使用

判断不为空
<if test="compShopMO.uciCompName != null and compShopMO.uciCompName != ''">
    and USER_COMPANY_INFO.UCI_COMP_NAME = #{compShopMO.uciCompName}
</if>

判断为空
<if test="compShopMO.uciCompName == null or compShopMO.uciCompName == ''">
    and USER_COMPANY_INFO.UCI_COMP_NAME = #{compShopMO.uciCompName}
</if>