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Update Statement

Author

Topic

maya_zakry
Constraint Violating Yak Guru

379 Posts

Posted - 2007-01-05 : 21:38:38

hi all,
how to update a column to the column itself?
i mean i have the scenario that i need to update 10 column at a time but actually 3 will need the real update, the rest i need to reserved the value. My SP will send value s1 til s10 param.. the Q is what value i need to assign to s1 if i want to reserved the old value? maybe something like...

UPDATE tblblabal
SET s1=??,
s2='change2something',
s3='change2something'
til s10

maybe u would ask, why update s1 if u dun wanna update it? it's because i need to prepare for 'needtochange' scenario from my codebehind(vb.net)..

maya_zakry
Constraint Violating Yak Guru

379 Posts

Posted - 2007-01-05 : 21:48:19

this would be no prob without any param..(direct sql)

UPDATE tblblabal
SET s1=s1 <--- setting to its column name will change nothing
s2='change2something',
s3='change2something'

but then if in the stored proc, how do i set the param valum to the column name in my codebehind????

my SP:-

@s1 as varchar(10),
@s2 as varchar(10),
@s3 as varchar(10),

how to set the @s1 to the name of the table column from the codebehind??escape char??

madhivanan
Premature Yak Congratulator

22864 Posts

Posted - 2007-01-05 : 23:38:23

Before trying this make sure you have backup of that table

Send NULL value to that S1 provided your Sp is

Create Procedure Test(
@s1 as varchar(10),
@s2 as varchar(10),
@s3 as varchar(10)
) as

UPDATE tblblabal
SET s1=ISNULL(@s1,s1)
s2='change2something',
s3='change2something'

Now Execute SP by

EXEC Test NULL,'somevalue','somevalue'

Madhivanan

Failing to plan is Planning to fail

maya_zakry
Constraint Violating Yak Guru

379 Posts

Posted - 2007-01-08 : 02:59:10

hi madhivanan..

this seems to work, but it doesnt.. i dunno what's wrong, it keeps entering null intead of old value

maya_zakry
Constraint Violating Yak Guru

379 Posts

Posted - 2007-01-08 : 03:12:07

finally it works, tq ! but another Q :-
how do we send null value from the codebehind? (vb.net?>

maya_zakry
Constraint Violating Yak Guru

379 Posts

Posted - 2007-01-08 : 03:15:54

System.DBNull.Value