How do you keep the order using SELECT WHERE IN()?

问题

Is there a way to keep the order when using SELECT WHERE IN()? For example, using the following query:

SELECT id FROM data_table WHERE id IN(56,55,54,1,7);

The results will come back using the default order by id. 1,7,54,55,56

When I want to keep the order used in the IN: 56,55,54,1,7

Is there a quick way to do this in mySQL or will I be forced to order it after in code.

Thanks :)

回答1:

Use FIND_IN_SET:

ORDER BY FIND_IN_SET(id, '56,55,54,1,7')

回答2:

You can also use FIELD:

ORDER BY FIELD(id, '56,55,54,1,7')

• http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_field
• http://ivanjovanovic.com/2008/04/01/preserving-ordering-with-where-in-clause-in-mysql/

回答3:

You could do a UNION, that might return the order the same way.

BUT:

Why not just have your application reorder the results when it receives them, rather than forcing the DB to do it?

来源：https://stackoverflow.com/questions/2813884/how-do-you-keep-the-order-using-select-where-in