I have 1 table having 40 columns. This will accomplish the changes in all columns at once. Also if your table already has data with null values on those columns, you will have to define default values as well. Here is a sample:. You could first update the table containing existing NULLs with appropriate value before running this. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more.
How to set all column from null to not null in table in oracle Ask Question. Asked 3 years, 9 months ago. Active 3 years, 3 months ago. Viewed 12k times. Generate a script from the data dictionary? The reverse of this, maybe? How are you going to provide values for the columns which currently are set to NULL?
Add a comment. I thought it would be best to put a unique Function Based Index on this and enable no validate it, job done.
Where am I going so massively wrong?? Thanks, Mike. September 17, - am UTC. The only thing I could think of off the top of my head is, that while they are "cleaning up", you would use an IOT as your "unique index" and a trigger to maintain it. Thanks - Can I just check that Mike, September 21, - am UTC. I know this smacks of "Just let it go" but I just wanted to make sure that my understnading is correct.
I thought of the following I can't do. And I understand this is my fault, I have to mark it as unusable and it won't skip it as it is unquie, Fair Enough. In fact you can't even enable no validate an index which makes sense.
I guess I just can't do this can I? The only reason I ask is that instead of the suggestion above I could do the old multi triggers with the mutating table catch.
This seems less implementation effort to me? Thanks as ever, Mike. September 21, - pm UTC. There are a handful of FK's between the tables even though they are many columns that can be made FK's. These columns that can be made FK's have currently have a lot of invalid data. I would like to know your suggestions on the following If we create a foreign key with noValidate constraint are they going to be any problems with 1a SQL performance 1b Indexes and 1c Materialized views 2 Does anythig change because an FK has a noValidate constraint.
Thanks and Regards. December 28, - pm UTC. As an end user, or an ad-hoc query tool, or whatever -- you have just lied to us. A foreign key is the fastest, least resource intensive all around best way to ensure data integrity. Suggest you go through a data cleansing operation, not an attempt to hide the issue under the rug. Tom, I agree with every single word of what you have said. I tried to get the data cleaned, but it is a huge effort. So while the data is being cleaned I would like to set up the noValidate constraint.
I just needed a confirmation from you before I could chew up the developers who put us in this mess. Thank you. Hi Tom, I just had a quick read of this thread but didn't see this point so I just thought I'll mention it as it can be a little trap for the unwary when using novalidate constraints and it doesn't involve query rewrites.
However, if one enables the constraint with novalidate Similar problems can be encountered for other check constraints as well. Strangely, attempting to select data that can't exist or the requirement for an empty set is more common than many realize. Cheers Richard Foote. A reader, January 19, - pm UTC.
I have a table with approx , rows. I need to create a unique constraint on two of the columns that should be enforced for any future rows. I am using Oracle 8. I do not want to create the index, I would rather rely on Oracle features, since the manual says this is a better way of creating unique constraints. How can I enforce the constraint only for new rows? I cannot clean up the table and get rid of duplicate data.
February 22, - pm UTC. I mean, you have duplicates already - tables do not have a "percentage of data integrity", they either a are b are not and in the future, how do you determine "rows that are OK to be non-unique" versus everything else? Yes, I do have a primary key for this table being generated by a sequence. I can always pinpoint a unique row based on this primary key, however I need to establish a new constraint with two columns as unique the columns are not part of primary key, but are Foreign key to another table.
Is there a way around this short of getting rid of duplicate records? February 23, - am UTC. N is the current value or the value that which you want all rows unique col1, col2 are the columns in question. Foreign Key documentation in the database? I've got a data warehouse and marts where the referential integrity is ETL-enforced. However, it's a pain to reverse-engineer the data structures in ERwin or any other data modeling tool because the RI is not documented in the database.
June 17, - pm UTC. You can comment on tables - using the comments command and on columns. ETL tool might be programmed wrong. Hi Tom. August 25, - pm UTC. A problem after recovery A. Semenov, February 15, - am UTC. Could you help me with my problem I use Oracle9i DB in archivelog mode. And after next system crash the DB was recovered. Everything seemed good but then I found the following problem. And it was noticed that the two last inserted before crash records were found "absent" with existing corresponding details to these records with foreign key constraint on this field.
February 15, - am UTC. Semenov, February 15, - pm UTC. We can give the custom name to the Not Null constraint also. Here is the example to demonstrate it. If you try to add a not-null constraint on the column containing null values, then that command will fail as it will validate all the rows all the existing rows for not null constraint. Sometimes we want to keep the existing null values and check for future rows that they contain a not null value for this column, then, in that case, we may enable the constraint with novalidate clause.
With this clause, it will not check the existing rows, but future rows will be checked.
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