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Asked: 2026-05-14T00:51:00+00:00

This is what i am doing update t1 set x=a,y=b where a and b

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This is what i am doing

update t1 set x=a,y=b where a and b are obtained from (select query here)
  1. I know the select query
  2. The select query returns multiple results which are the same
  3. When I use group by or distinct query execution slows down considerably
  4. a and b are forward references so mysql reports an error
  5. I want to set a equal to the value obtained in the first row and b equal to the value obtained in the first row for the respective columns, to avoid group by. I don’t know how to refer to the first result from the select query.

How can i achieve all this?

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1 Answer

  1. Editorial Team

    LIMIT specifies the number of rows to return from the beginning of the result set:

    SELECT * FROM t2 LIMIT 1; # Retrieve 1st row

    LIMIT in your case is applied in the subquery in your from clause.

    These linsk can help you out with update that uses a subquery:

    Update with Subquery

    Subqueries in MySQL, Part 1

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