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Get field value before updating

Is there a way to get the value before and update the request in the update request itself?

For example:

UPDATE t SET field1 = 'new', field2 = IF (field2 = field1, 'new', field2))

In 'field2 = field1' I want to check the previous field value. Mysql works in such a way that it updates field1 and then will compare with the new value, so it will always have the value "IF (field2 =" new ", ..."

So, I would like something like

UPDATE t SET field1 = 'new', field2 = IF (field2 = PREVIOUS_VALUE(field1), 'new', field2))

Updated:

swapping may not work sometimes in more complex examples when I want it to be like this:

UPDATE t SET field1 = IF (field1 = PREVIOUS_VALUE(field2), 'new', field1)), field2 = IF (field2 = PREVIOUS_VALUE(field1), 'new', field2))
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2 answers


Just rebuild these sets.

UPDATE t
SET 
field2 = IF (field2 = field1, 'new', field2),
field1 = 'new';


Demo: http://sqlfiddle.com/#!2/bb265/1

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Try in reverse order:



UPDATE t SET field2 = IF (field2 = field1, 'new', field2), field1 = 'new'
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