How can I add data in another column with the result of another column?

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How can I add data in another column with the result of another column?

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#1 by (0 votes)

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I have the following scenario and need to add the result of a Select in another column of the same table, for example, a column with the numbers and another column to check how often these numbers appear: / p>

números|frequência
 1     | 2
 2     | 1 E assim por diante.

I was able to do a select that shows and shows the frequency, as below, but I do not know how to add the result that is the frequency in another column, since I need to use the results of those columns in HTML .

Select to check the frequency:

select  distinct id, CONCAT(numeros, "frequencia",count(id)) as Numeros from tb_numeros group by numeros;

The result is working out for now:

[{"id":1,"Numeros":"1 - frequencia - 3"},{"id":2,"Numeros":"2 - frequencia - 1"}]

Thank you very much for your attention!

mysql

asked by anonymous 06.11.2017 / 01:56

1 answer

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score 0 · Answer 1

Just doing an update with a subselect in mysql would be like this

UPDATE tabela1 t1 JOIN tabela2 t2 ON t1.id = t2.id
SET t1.col1 = t2.col1, t1.col2 = t2.col2, ...

or

   update table1 t set
column1 = (select column1 from old_table where id = t.id),
column2 = (select column2 from old_table where id = t.id);

see the form you find easiest