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    Sql updating a table from itself

    Because you refer to the same table twice in the same statement, you have to use table aliases.

    The SQL UPDATE VIEW command can be used to modify the data of a view.

    We consider each event as having 2 statuses that are based on detail and calculations from the prior logged events for the same item. Item ID and Message Time So, the question is, how can I update the Status1 and Status2 columns in the table to be the Calculated_Status1 and Calculated Status2 columns? 10 THEN 'Good' ELSE 'Bad' END Calculated_Status2 FROM Item Log A, (SELECT F.

    So, I've developed a SELECT query that uses multiple self-joins to analyze factors from prior events relative to each event, and calculates the statuses. I've tried taking my calculation query and joining it to the table by the 2 primary keys, but I get the "ORA-01779: cannot modify a column which maps to a non key-preserved table" error.

    I had to do a very simple Microsoft SQL query in which I wanted to update some of the values in a row from a row in the same table.

    It said that if I want to update a table from a source I need to use the FROM keyword, like this: As you can see, we use an alias to name another table or query, we use the Alias name for all the conditions for that table and nothing for the conditions on the table we update. However, the number of updated columns was always 0.

    Remarkable how difficult it is to find on the net a straight answer about a simple situation like this.

    Message Time= SELECT MAX(Message Time) FROM Item Log WHERE Item ID=F.

    Taking out the criteria so that all 2500 rows updated took 40 seconds.

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