SQL alter table modify column

ALTER TABLE Persons
ALTER COLUMN DateOfBirth year

sql conditional insert,update,delete with merge command

declare @target table
(
id int,
lead_id int
)
insert into @target(id,lead_id) values(1,521),(2,521),(1,13),(2,13)
--select * from @target

declare @source table
(
id int,
lead_id int
)

insert into @source(id,lead_id) values(2,521),(3,521),(4,521)
--select * from @source

merge into @target as ttable
using @source as stable
on stable.lead_id = ttable.lead_id and stable.id = ttable.id
when NOT MATCHED then
INSERT (id,lead_id)
VALUES(stable.id,stable.lead_id)
WHEN NOT MATCHED BY SOURCE
AND ttable.lead_id IN(521) THEN
        DELETE;

select * from @target

sql alter table drop column

ALTER TABLE trn_l DROP COLUMN cash

SQL Convert varchar to varbinary

CAST('Fine' AS VARBINARY(MAX))

SQL check null in where condition

 where (ISNULL(NULLIF(@tptCode,''),N'') =N'' OR msl.tpt_cd= @tptCode)     

SQL Like query

select login_id,first_name + ' ' + last_name as name,'0' as evuda,count(*) over () as [record_count]
from userinfo
where comp_id = @LoginCompId
and first_name like '%'+ isnull(ltrim(rtrim(@UserName)),first_name) +'%'  
or last_name like '%'+ isnull(ltrim(rtrim(@UserName)),last_name) +'%'

SQL nested case when then

 CASE
WHEN alertcon.alert_type = 'E'
THEN
CASE
    WHEN alertgat.gateway_id = 'M' THEN escUser.login_id
    WHEN alertgat.gateway_id = 'E' THEN escUser.email_id
    ELSE ''
END
WHEN alertcon.alert_type = 'R'
THEN
CASE
   WHEN alertgat.gateway_id = 'M' THEN escUser.login_id
   WHEN alertgat.gateway_id = 'E' THEN escUser.email_id
    ELSE ''
END
END as Recepient