how to make a particular column null in database

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how to make a particular column null in database

Author

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mohan123
Constraint Violating Yak Guru

252 Posts

Posted - 2013-03-19 : 04:11:30

hello all,

i have two column created and modified columns in all tables in database.Almost these columns will come in all tables in entire database.So is there any way to make null these columns in one go like 300 tables. Suggest me .....

P.V.P.MOhan

bandi
Master Smack Fu Yak Hacker

2242 Posts

Posted - 2013-03-19 : 04:32:53

If all tables have created and modified columns, then use the follwoing sql code:

exec sp_MSforeachtable 'ALTER TABLE ? ALTER Column created DATETIME NULL'
GO
exec sp_MSforeachtable 'ALTER TABLE ? ALTER COLUMN modified DATETIME NULL'

NOTE: sp_MSforeachtable is undocumented procedure.So do not use in production server

--
Chandu

mohan123
Constraint Violating Yak Guru

252 Posts

Posted - 2013-03-19 : 04:51:41

while executing the above query if the table have created column it is making null but if the table doesn't have created column it is showing error like

ALTER TABLE ALTER COLUMN failed because column 'Modified' does not exist in table

how to overcome this one

P.V.P.MOhan

bandi
Master Smack Fu Yak Hacker

2242 Posts

Posted - 2013-03-19 : 05:24:41

Try this once........


exec sp_MSforeachtable 
'IF EXISTS ( SELECT 1 FROM sys.columns WHERE table_name = ? and column_name = ''created'' )
	ALTER TABLE ? ALTER Column created DATETIME NULL'

exec sp_MSforeachtable 
'IF EXISTS ( SELECT 1 FROM sys.columns WHERE table_name = ? and column_name = ''modified'' )
	ALTER TABLE ? ALTER Column created DATETIME NULL'

--
Chandu

visakh16
Very Important crosS Applying yaK Herder

52326 Posts

Posted - 2013-03-19 : 10:17:25

it should be


exec sp_MSforeachtable 
'IF EXISTS ( SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS WHERE ''['' + table_Schema + ''].['' + table_name + '']'' = ''?'' and column_name = ''created'' )
	ALTER TABLE ? ALTER Column created DATETIME NULL'

exec sp_MSforeachtable 
'IF EXISTS ( SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS WHERE ''['' + table_Schema + ''].['' + table_name + '']'' = ''?'' and column_name = ''modified'' )
	ALTER TABLE ? ALTER Column modified DATETIME NULL'

------------------------------------------------------------------------------------------------------
SQL Server MVP
http://visakhm.blogspot.com/

visakh16
Very Important crosS Applying yaK Herder

52326 Posts

Posted - 2013-03-19 : 10:19:34

quote:

Originally posted by bandi

Try this once........


exec sp_MSforeachtable 
'IF EXISTS ( SELECT 1 FROM sys.columns WHERE table_name = ? and column_name = ''created'' )
	ALTER TABLE ? ALTER Column created DATETIME NULL'

exec sp_MSforeachtable 
'IF EXISTS ( SELECT 1 FROM sys.columns WHERE table_name = ? and column_name = ''modified'' )
	ALTER TABLE ? ALTER Column created DATETIME NULL'

--
Chandu

wont work like above

1. ? returns fully qualified tablename ie [schema].[tablename]
2. sys.columns doesnt have table_name column so should be using INFORMATION_SCHEMA.COLUMNS table instead
3. for using table name as string use '' around ?

------------------------------------------------------------------------------------------------------
SQL Server MVP
http://visakhm.blogspot.com/

bandi
Master Smack Fu Yak Hacker

2242 Posts

Posted - 2013-03-20 : 00:40:05

Yes... that is my mistake...
I haven't checked above query with sys.columns....

--
Chandu

mohan123
Constraint Violating Yak Guru

252 Posts

Posted - 2013-03-20 : 00:43:54

yeah thanks...my work got over in first question itself

ALTER table name check check constraint ALL this query done trick for making all noCHECK constraint to Check constraint ....thanks chandu and visakh

P.V.P.MOhan

bandi
Master Smack Fu Yak Hacker

2242 Posts

Posted - 2013-03-20 : 00:51:54

quote:
Originally posted by mohan123

yeah thanks...my work got over in first question itself

ALTER table name check check constraint ALL this query done trick for making all noCHECK constraint to Check constraint ....thanks chandu and visakh
P.V.P.MOhan

Welcome...

--
Chandu

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