following [this improvement][1],

[1]: http://oslandia.com/en/2017/10/07/refresh-your-maps-from-postgresql/ and the video inside the link, I am trying to refresh automatically a layer. I select the option in the render tab in the properties, but did not use any message for now. I insert a new polygon in my postgres database. Then I use the psql command NOTIFY qgis ; Nothing happens in Qgis. The question is why the canevas does not refresh despite the notify executed from the psql shell. Postgres 9.3 Qgis 2.99 4a2da5006b

closed as off-topic by underdark Jan 19 '18 at 19:09

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions seeking help to debug/write/improve code must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Providing a clear problem statement and evidence of a code attempt will help others to help you. See: How to create a Minimal, Complete, and Verifiable example." – underdark
If this question can be reworded to fit the rules in the help center, please edit the question.

  • Show an example about how you write your transactions from BEGIN; up till COMMIT; – user30184 Jan 17 '18 at 10:19
  • for now, there is no transaction. I am just trying the simple way described in the link I gave. I checked qgis layer, inserted a polygon, then used notify in psql. No result. If I manualy refresh the layer, I can see the new entitie, not with notify. – Leehan Jan 17 '18 at 10:25
  • This is the Question equivalent of a link-only answer. Please Edit the question to state what you are attempting in the body of the question. You should alway edit the question in response to requests for clarification. It's not fair to those who would answer to need to mine the comments for critical information. – Vince Jan 17 '18 at 12:56
  • This is from the link that you provided Caveats Notify signals are only transmitted with the transaction, so when the COMMIT is raised. If you do not make transactions then you just waste your time. – user30184 Jan 17 '18 at 14:06
  • Well, in the video int he link provided, the user only uses UPDATE. There is no transaction with begin commit, if I am right. – Leehan Jan 17 '18 at 14:24

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