查询一级类目下 2级 3级 4级 对应的数量
SELECT temp.cname,temp.rootcid, (SELECT COUNT(1) FROM show_tb_category t1 WHERE t1.flag=2 AND t1.rootcid=temp.rootcid)category2, (SELECT COUNT(1) FROM show_tb_category t1 WHERE t1.flag=3 AND t1.rootcid=temp.rootcid)category3, (SELECT COUNT(1) FROM show_tb_category t1 WHERE t1.flag=4 AND t1.rootcid=temp.rootcid)category4 FROM (SELECT rootcid,flag,cname FROM show_tb_category WHERE flag=1 ORDER BY cid) temp
查询1,2,3,4级类目总的数量
SELECT SUM(CASE t.flag WHEN 1 THEN 1 ELSE 0 END) AS count1, SUM(CASE t.flag WHEN 2 THEN 1 ELSE 0 END) AS count2, SUM(CASE t.flag WHEN 3 THEN 1 ELSE 0 END) AS count3, SUM(CASE t.flag WHEN 4 THEN 1 ELSE 0 END) AS count4, COUNT(t.flag) AS counTotal FROM show_tb_category t