SQL Server 2019

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select @@version;


(No column name)


Microsoft SQL Server 2019 (RTM-CU6) (KB4563110) - 15.0.4053.23 (X64) 
 Jul 25 2020 11:26:55 
 Copyright (C) 2019 Microsoft Corporation
 Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)



create table t (id INT, name varchar(10), age INT, contact INt ,gender varchar(20));
insert into t values (1, 'ABC',NULL, 8876, NULL);
insert into t values (1, 'ABC', 15, NULL, NULL);
insert into t values (1, 'ABC', NULL, NULL, 'Male');
3 rows affected

select * from t;



id
name
age
contact
gender


1
ABC
null
8876
null

1
ABC
15
null
null

1
ABC
null
null
Male


select id, name, max(gender) as gender, max(age) as age, max(contact) as contact
from t
group by id, name


id
name
gender
age
contact


1
ABC
Male
15
8876


Warning: Null value is eliminated by an aggregate or other SET operation.