MySQL node does not give the same query

I have this test, and MySQL node does give the same query

I just test this query, it gives 2 different data when the node is the same

  1. It run alone
  2. It run with other node before connected

If run these 2 same copy nodes which connect them together, the same issue happened!
It seems alone node and connected node has issues with some of query syntax:

  1. Alone: right data of query
  2. Connected: wrong data, with so many other duplicated rows

Hey @cmdntd987,

Let me try to explain why you’re facing this issue. Let’s say the first MySQL node returns 10 items. The next node (MySQL or any other node) will iterate 10 times, resulting in duplicate values. This is expected behavior in n8n. To avoid this, you should set the Execute Once option to true.

Hope this helps :slight_smile:

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Well, it’s very helpful

But I ran this many times. Why this caused the same way?
I do not realize any problem in way how node could run many times. Like use 2 same node, in fact, it only query in 1 time, does n’t it?