用一个字段的不同的值来执行不同的sql语句当不传值时为什么也会执行

SELECT a.* FROM recruit_prj_info a,recruit_items_info b


AND a.employ_id = #{userId}


AND a.recruit_name = #{recruitName}


AND a.recruit_phone = #{recruitPhone}


AND b.item_type = #{itemType}


AND a.state = #{state}


AND a.addr_prov=#{addrProv}


AND a.addr_city=#{addrCity}


AND a.addr_area=#{addrArea}

AND DATE_FORMAT( a.cre_time, '%Y%m' ) = DATE_FORMAT( CURDATE( ) , '%Y%m' )

AND QUARTER(a.cre_time) = QUARTER(NOW())

AND a.cre_time BETWEEN date_sub(now(),interval 6 month) and now()

AND a.cre_time BETWEEN date_sub(now(),interval 12 month) and now()

AND a.recruit_id=b.recruit_id GROUP BY a.recruit_id ORDER BY a.cre_time DESC

当我不传 recruitTime 的时候会默认执行 recruitTime=3里面的sql条件
请问下大神这是什么原因呢

当我不传值时也会执行等于3时候的sql语句
传值了就没有问题 请问下这是什么原因照成的

select放在外面包一层

不觉得这串sql语句太多的and吗？