All legitimate Oracle experts publish their Oracle qualifications. Oracle technology is changing and we strive to update our BC Oracle support information. If you find an error or have a suggestion for improving our content, we would appreciate your feedback. Just e-mail: and include the URL for the page. All rights reserved by Burleson. Search BC Oracle Sites. Conditionally update data in table A based on a common column in table B. The query below does NOT work for this conditional update.
Update data in table A based on two or more common columns in table B. Updates based on two or more common columns are normally used for tables where multiple columns work together as a primary key known as composite primary key. These columns uniquely identify a record in a table. Happy updating! Get single records when duplicate records exist 2. Find duplicate values or non-duplicate values in a table 3. How the data types in Access Northwind are converted to Oracle 6. You can also catch regular content via Connor's blog and Chris's blog.
Or if video is more your thing, check out Connor's latest video and Chris's latest video from their Youtube channels.
And of course, keep up to date with AskTOM via the official twitter account. Questions Update table with multiple columns from another table? Question and Answer. You Asked Hi Tom, Due to migration to new system we have to change all our account numbers.
Don't you mean June 28, - pm UTC. That means something doesn't it A reader, June 29, - am UTC. Hi Tom, Thanks for answering my question.
You told me to use update select old. How to update multiple columns in single SQL? In your answer only one number say client number will get updated. If it is not possible can you show me how to write "GOOD" sql? June 29, - am UTC. You need to have the table you are updating from have a unique or primary key constraint.
Update chithra, September 28, - am UTC. I had a similiar query and i tried applying to my tables. But when i did the same with the syntax given i got this error ora cannot modify a column which maps to a non key preserved value. Can you please clarify.
September 28, - am UTC. If you are 2 tables owned by different users, you will need update rights on both the tables even when you are updating only 1 table. I tried doing the same through this update select old. April 28, - am UTC.
Using join in select statement is very fast! I think it will work faster. May 05, - am UTC. May 06, - am UTC. Here you want to set a qty to a constant for some records - and you 'anti-join' to the other table, not join. You want to join basically three tables together, I can envision that jobs. Thanks for your input! After analyze table table2 compute statistics everything is ok. The original update works very fast now! Thanks again!
Pedro, May 14, - am UTC. Hello Tom. I have a problem similar to this, but probably a little simpler, but I can't make it to work I have 2 tables, one having a subset of columns the other has, i. May 14, - pm UTC. I did not follow this - sorry, not sure what you need.
Pedro, May 15, - am UTC. Name, table A. Marital Status where table A. May 19, - pm UTC. Just join. But if i update millions is there any other way?
May 28, - am UTC. Tilak, May 29, - am UTC. Is it better to go for Create Table as Select update info???? Many thanks,. May 29, - pm UTC. Tilak, June 04, - am UTC.
Create Table works quicker! But i cant use the create for limitations on downtime of the table. Dont want the table to be dropped and recreated. Unfortunately i cant get the tkprof as i dont have access to. Is there any other way i can use to speed up the update by any efficient means! June 04, - pm UTC. I cannot tell you how to make something more efficient if I do not know what is impeding the efficiency in the first place.
Tom, Is there workaround for the following? Thank you. September 26, - pm UTC. Update from other table geoff, October 06, - am UTC. Dear Tom, You mentioned previously that we need to have the table we are updating from to have a unique or primary key constraint. What if i need to update a table using data from an external table? The way i understand it external tables don't have primary keys.
I don't think i can use the merge statement here since there are more than 1 condition that has to be met for the target table to be updated. Any ideas? Thanks very much! October 06, - pm UTC. Update using external tables geoff, October 06, - pm UTC. Hi Tom! I have followup questions: 1. Can we put several conditions in the ON clause? And why do i get an 'invalid column name' error when i run this? October 07, - pm UTC. The merge statement is fully documented Dan, October 08, - am UTC.
October 08, - pm UTC. Hello Tom, I've been using join updates for some time, but recently I run into an unexplained behavior from Oracle. Here is a short demonstration I'm using Does it mean, that in order to be able to use join updates, we need to build the join conditions only based on the values in both tables, and cannot use directly provided values? You may ask for a real-world scenario to use such syntax.
Which produces the ORA error for exactly the same reasons, as in the simplified example above. I have a workaround, so this is not a big problem, but I'm just wondering if there is any reason for such situation?
0コメント