Updating data from one table to another Online chats for free without regatrations


24-Dec-2019 17:58

When the subquery fails to find a matching row in tbl B, the subquery returns NULL.

But since the UPDATE has no WHERE clause, it will update all rows, even those where the subquery returns NULL.

The query would in fact execute without any error messages since the correlated subquery in SET clause returns EXACTLY one row for each row in B and the where clause executes without error. Lets say you have a table A ( id int, a1 varchar2(25) ) and a table B ( id int PRIMARY KEY, b1 varchar2(25) ). But I am not able to identify the correct record to update. Thanks January 02, 2004 - am UTC and i, not knowing how your data all fits together, cannot say would need an example (complete, yet concise, with sample data and an explanation of how the data all fits together) hi tom , desc child_table-------------------child_id number ;child_birth_date date;child_20_flag number(1) ; where the child_20_flag should indicate if the child reach 20 years old or , what is the best way to handle it automaticlly ?

Visit Stack Exchange Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. Sign up to join this community I have one table A has column (id, field_1,field_2), and another table B has column (id,field_2) Now I want to merge table B to A, that means i want to update field_2 in table A to value of table B. BTW I am using oracle Thanks Now, each time the above is executed, it will do it across all rows in the table.

If this is something you need to do all the time, I would suggest something else, but for a one-off or very small tables it should be sufficient.

Next, build the query like the one below: This query will update the MFG field in the Bot table with the value in the MFG field in the Big table when the PART values match.

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.I am think of the way without using cursor, script as below. I am getting current year data first into above table after I am trying to update previous year amount.