1 select * from t_hq_ryxx; 2 3 select nianl, xingm from t_hq_ryxx; 4 5 select nianl as 年龄, xingm as 姓名 from t_hq_ryxx t; 6 7 select nianl 年龄 from t_hq_ryxx; 8 9 select nianl || xingm as 年龄和姓名 from t_hq_ryxx; 10 11 select nianl as hhh,t.* from t_hq_ryxx t order by nianl desc ;--排序 12 13 select nianl as hhh,t.* from t_hq_ryxx t order by xingb desc ,bum desc; 14 15 select nianl,xingm,bum,xingb from t_hq_ryxx t order by bum desc nulls last,xingb; 16 17 select * from t_hq_ryxx order by 3; 18 19 select nianl,gongz, (nianl+gongz)as g from t_hq_ryxx order by (gongz||nianl); 20 21 --去重复 22 select distinct bum from t_hq_ryxx; 23 24 select distinct bum,xingb from t_hq_ryxx; 25 26 select * from t_hq_ryxx; 27 28 29 select * from t_hq_ryxx where xingb = '1 'and bum = '102'; 30 31 select * from t_hq_ryxx where (bum = '101' or bum = '102') and xingb = '2'and nianl >'40' ; 32 33 select * from t_hq_ryxx where bum is not null; 34 35 --模糊查询 %表示通配符 36 37 select * from t_hq_ryxx where xingm like '三%' 38 39 select * from t_hq_ryxx where xingm like '%儿' 40 41 select * from t_hq_ryxx where xingm like '%三%' 42 43 select * from t_hq_ryxx where gongz <any (select pingjgz from t_hq_bm); 44 45 --值得范围 46 select * from t_hq_ryxx where nianl in ('33','58'); 47 48 select * from t_hq_ryxx where nianl ='33' or nianl = '58'; 49 50 --区间范围 51 52 select * from t_hq_ryxx where gongz between 40 and 100; 53 54 select * from t_hq_ryxx where gongz >=40 and gongz <= 100; 55 56 --子查询 57 select * from t_hq_ryxx where bum in (select bumbm from t_hq_bm where lianxdh = '10086'); 58 59 --大于最小值,小于最大值 60 61 select * from t_hq_ryxx where gongz >any (select pingjgz from t_hq_bm); 62 63 --大于最大值,小于最小值 64 65 66 select * from t_hq_ryxx where gongz >all (select pingjgz from t_hq_bm); 67 68 --分组 多种形式 69 select bum from t_hq_ryxx group by bum; 70 71 select bum,count(1) as 数量 from t_hq_ryxx group by bum; 72 73 select bum,count(1) as 数量,sum (gongz) as 合计 from t_hq_ryxx group by bum; 74 75 select bum,count(1) as 数量,avg(gongz) as 平均值 from t_hq_ryxx group by bum; 76 77 select nianl, bum,count(1) as 数量,avg(gongz) as 平均值 from t_hq_ryxx group by nianl, bum; 78 79 select bum,count(1) as 数量,avg(gongz) as 平均值 from t_hq_ryxx group by bum having avg(gongz)>60; 80 81 82