Oracle multiple processes updating same table
That's how you can do ittable busstopsid | route | busstop | pos1 | 1 | A | 1 2 | 1 | B | 2 3 | 1 | C | 3 4 | 2 | C | 1 5 | 2 | D | 2 6 | 2 | A | 3 7 | 2 | E | 4 8 | 2 | F | 5 9 | 2 | G | 610 | 2 | H | 7Moving D, E, F, G To route 1 SET @pos=(SELECT max(t1.pos) FROM busstops t1 WHERE t1.route = 1 ); UPDATE busstops SET pos = ( SELECT @pos := @pos 1 ), route =1 WHERE id IN (5,7,8,9)I doubt this could be done otherwise since referencing the table you wish to update within the subquery creates circular references After DELETE or UPDATE i.e.
when a row of a subset is lost/deleted/moved away from it, the whole subset will need to be reordered.
If you update a column that has been declared , an error occurs if strict SQL mode is enabled; otherwise, the column is set to the implicit default value for the column data type and the warning count is incremented.
The implicit default value is tables for which there are foreign key constraints, the My SQL optimizer might process tables in an order that differs from that of their parent/child relationship. Instead, update a single table and rely on the provides to cause the other tables to be modified accordingly. COLUMN2 IS NULLAn outerjoin is performed based on the equijoin condition.
If UPDATE gives an error like this:"You are using safe update mode and you tried to update a table without.."..it may be that your file must be edited to disable safemode. In order for the change in the file to take effect, you must have permission to restart mysqld in the server OS environment.Here is a way to use multiple tables in your UPDATE statement, but actually copying one row values into the other, meaning, we're using the same table: UPDATE jobs AS to Table, jobs AS from Table SET to Table.job_type_id = from Table.job_type_id, to Table.job_company_id = from Table.job_company_id, to Table.job_source = from Table.job_source, WHERE (to Table.job_id = 6) AND (from Table.job_id = 1)--------------Pretty cool.