title: MySQL convert Trigger from Update to Insert
body: <p>I have an AFTER UPDATE Trigger that performs an UPDATE. I’ve been trying to convert the Trigger from an AFTER UPDATE UPDATE to an AFTER UPDATE INSERT to see if the performance is better. I however cannot get it close to working.</p>
  <p>Most of my attempts have involved trying to use INSERT INTO with a SELECT statement, but I get unknown column errors and multiple errors related to my WHERE clauses. My latest error is: “Operand should contain 1 column(s)”</p>
  <p>Expected Outcome: When a column in Table1 is updated, then INSERT the matching rows(by id,session) from view1 into Table3. An INSERT into Table3 for id1 might look like:</p>
  <pre><code>id | session | results1 | results2 | results3
  1      1          BCE      GOOG      TSLA
  1      2          S&amp;P      ARKK      TSLA
  </code></pre>
  <p>The current UPDATE trigger updates each column independently, I would like the whole row inserted, like the example above.</p>
  <p>The fiddle should help it make more sense: <a href="https://dbfiddle.uk/?rdbms=mysql_8.0&amp;fiddle=56868344c95a250b47899c47471576be" rel="nofollow noreferrer">https://dbfiddle.uk/?rdbms=mysql_8.0&amp;fiddle=56868344c95a250b47899c47471576be</a></p>