源表:
idname addv_num
1 AAA abc
1
1 AAA bcd
2
1 AAA cde
3
2 BBB cdf
1
2 BBB dfg
2
3 CCCggg
1
4 DDDefg
要求:找出 v_num 最大 或者 是 null 的记录:
结果应该是:
1 AAAcde 3
2 BBBdfg 2
3 CCC ggg1
4 DDD efg
scripts:
create table test (
id int,
name varchar2(20),
addvarchar2(20),
v_num int);
insert into test values (1, 'AAA', 'BCD', 1);
insert into test values (1, 'AAA', 'CDE', 2);
insert into test values (1, 'AAA', 'DEF', 3);
insert into test values (2, 'BBB', 'BCF', 1);
insert into test values (2, 'BBB', 'CDF', 2);
insert into test values (3, 'CCC', 'GGG', 1);
insert into test values (4, 'DDD', 'EFG', NULL);
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