Timeline for Update column with another table's value
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 16, 2017 at 18:30 | comment | added | indiri | If it does not have a unique constraint then include a line in the subquery to limit it to 1 result | |
| Sep 16, 2017 at 17:46 | comment | added | stefan | Updating the subquery (containing the join) only works if the users table has this constraint (it's a built-in restriction). It was just an example. The new ids must go somewhere - I did not want to overwrite existing values. | |
| Sep 16, 2017 at 17:39 | comment | added | indiri | Also your dbfiddle does not seem to match the original question. The original question said that username and email are mixed in the same column is user_details but in fiddle they are separate columns. Also in the original you were updating user_details.username=users.id but now you want to use a new column and put the user_details.user_id=users.id. The attached fiddle does not have any situations where there would be more than one users.id that matches. | |
| Sep 16, 2017 at 17:35 | comment | added | indiri | If you take UNIQUE out of users in the dbfiddle? So you mean that multiple users may have the same email address. In that case (more than one user has that email) are you intending to just pick whichever one is first? Or do you not want to do the update if there is more than 1? | |
| Sep 16, 2017 at 17:15 | comment | added | stefan | dbfiddle.uk/… | |
| Sep 16, 2017 at 17:04 | comment | added | indiri | When there is more than 1 then how are you determining which one you want? | |
| Sep 16, 2017 at 17:03 | comment | added | stefan | If there is more than one users.sid, we'll get a "ORA-01427: single-row subquery returns more than one row." (Although: at the first glance I thought your UPDATE should do the job :-)) | |
| Sep 14, 2017 at 21:15 | history | answered | indiri | CC BY-SA 3.0 |