优化sql：select sbr.name, sbr.sex, sbr.id_card, IF(sbs.id_card is null,'否','是') is_basic_living, sbr.nation, sbr.birth_date, sbr.phone, sbr.educational_status, sbr.is_old, sbr.is_basic_living, sbr.area_id, sbr.house_id, sbr.community_id, sbr.unit_id, sbr.building_id, sbc.community_name as communityName, sba.area_name as areaName, sbb.building_name as buildingName, sbu.unit_name as unitName, sbh.`name` as houseNo, (SELECT ITEM_VALUE FROM pub_dict_item WHERE DICT_CODE = "SC_NATION" and ITEM_CODE = sbr.nation) as nation, (@i := @i+1) AS seqNo from sc_basics_resident sbr left join sc_basics_houses sbh on sbr.house_id = sbh.house_id left join sc_basics_unit sbu on sbr.unit_id = sbu.unit_id left join sc_basics_building sbb on sbr.building_id = sbb.building_id left join sc_basics_area sba on sbr.area_id = sba.area_id left join sc_basics_community sbc on sbr.community_id = sbc.community_id left join sc_basics_special sbs on sbs.id_card = sbr.id_card ,(SELECT @i:=0) AS iTable;

你可以对这个SQL查询进行一些优化。首先，你可以尝试使用索引来加快查询速度。确保sc_basics_resident表中的house_id、unit_id、building_id、area_id和community_id列以及sc_basics_houses、sc_basics_unit、sc_basics_building、sc_basics_area和sc_basics_community表中对应的列上都有索引。

另外，你可以考虑将子查询(SELECT ITEM_VALUE FROM pub_dict_item WHERE DICT_CODE = "SC_NATION" and ITEM_CODE = sbr.nation)改为一个JOIN操作，将字典表pub_dict_item与sc_basics_resident表关联起来，以减少子查询的数量。

最后，你可以通过适当地分批查询数据，避免一次性查询过多的数据量，从而提高查询效率。