Update Item from same table where values are null - sql-server

Question

I have a table Member where their are duplicate entries and I want to remove one of them, but 1 of the entry has some columns updated and another has some other.
So What I want to do is update but the columns where values exist in 1 and null or empty in another so that both the rows become completely identical and I do not loose any data out of it.
Table Structure:
CREATE TABLE [dbo].[membermobilenumberisnull](
[TransId] [bigint] NOT NULL,
[member_id] [int] NOT NULL,
[gendertype] [int] NULL,
[relationship_rs_code] [nvarchar](2) NULL,
[ration_card_id] [int] NOT NULL,
[uid] [nvarchar](16) NULL,
[member_dob] [datetime] NULL,
[member_name_en] [nvarchar](150) NULL,
[mother_name_en] [nvarchar](150) NULL,
[father_name_en] [nvarchar](150) NULL,
[member_age] [smallint] NULL,
[nationality] [nvarchar](150) NULL,
[MobileNumber] [nvarchar](20) NULL,
[IsUpdated] [bigint] NULL,
[UpdationDate] [datetime] NULL,
[IsDeleted] [bigint] NULL,
[DeletionDate] [datetime] NULL,
[CreationDate] [datetime] NULL,
[UpdatedBy] [nvarchar](250) NULL,
[DeletedBy] [nvarchar](250) NULL,
[MobileNumber1] [nvarchar](20) NULL,
[MobileFlag] [nvarchar](250) NULL
) ON [PRIMARY]
GO
Sample Data
TransId member_dob member_name_en member_age nationality MobileNumber UpdationDate CreationDate
252238402 12-09-1985 PUSHPINDER SINGH 31 IND NULL 30-07-2016
252238403 12-09-1985 PUSHPINDER SINGH 31 IND 8626934377 NULL 30-07-2016
260846102 03-06-1984 VUDDHI DEVI 32 IND 9459209701 19-10-2016 14-08-2016
260846105 03-06-1984 VUDDHI DEVI 32 IND NULL 14-08-2016
Expected Result:
TransId member_dob member_name_en member_age nationality MobileNumber UpdationDate CreationDate
252238402 12-09-1985 PUSHPINDER SINGH 31 IND 8626934377 NULL 30-07-2016
252238403 12-09-1985 PUSHPINDER SINGH 31 IND 8626934377 NULL 30-07-2016
260846102 03-06-1984 VUDDHI DEVI 32 IND 9459209701 19-10-2016 14-08-2016
260846105 03-06-1984 VUDDHI DEVI 32 IND 9459209701 19-10-2016 14-08-2016
Thanks in advance
Example attached:

Answer 1

Assume your combined PK is member_dob,member_name_en,member_age
UPDATE M1
SET M1.MobileNumber = ISNULL(NULLIF(M1.MobileNumber,''),M2.MobileNumber)
,M1.UpdationDate = ISNULL(M1.UpdationDate,M2.UpdationDate)
FROM Member AS M1
INNER JOIN Member AS M2 ON M1.TransId <> M2.TransId
AND M1.member_dob = M2.member_dob
AND M1.member_name_en = M2.member_name_en
AND M1.member_age = M2.member_age

Answer 2

Try this
WITH t2 AS (
SELECT member_dob, member_name_en, member_age, nationality, MobileNumber
FROM <<table>>
WHERE MobileNumber IS NOT NULL
)
UPDATE t1
SET MobileNumber = t2.MobileNumber
FROM <<table>> t1 JOIN t2
ON t1.member_dob = t2.member_dob
AND t1.member_name_en = t2.member_name_en
AND t1.member_age = t2.member_age
AND t2.nationality = t2.nationality
WHERE t1.MobileNumber IS NULL

Answer 3

It seems you want to look at a member_name_en and take a value from whichever of its records, preferring non-null over null. Then simply aggregate and use MIN or MAX to pick such value.
update m
set member_dob = src.max_member_dob
, member_age = src.max_member_age
, nationality = src.max_nationality
etc.
from membermobilenumberisnull m
(
select
member_name_en,
max(member_dob) as max_member_dob,
max(member_age) as max_member_age,
max(nationality) as max_nationality,
etc.
from membermobilenumberisnull
group by member_name_en
) src on src.member_name_en = m.member_name_en;