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I am trying different queries in the Query Builder. Is there a way to comment the query? I tried with

/* */



without success :

An error occurred when executing the query. The data provider said: OGR[3] error 1: SQL Expression Parsing Error: syntax error


  • I have made a feature request of this question:

  • @Bernd V. observed that expressions are evaluated differently according to the format of the vector (see the [help] button in the Query builder for more information)

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Welcome to GIS! Unless I'm mistaken, I don't think you can comment queries in the Query Builder. – Joseph Jul 17 '14 at 12:18
Is there an other way to build queries then (and comment them as required ?) (Thx for editing, it looks much better) – nebi Jul 17 '14 at 12:48

2 Answers 2

up vote 4 down vote accepted

You can build queries by using the Query Builder or an alternative is to use the Expression string builder (Layer Properties > Style > select Rule-based > add a rule > insert your command in the Filter box or click the '...' button to bring up the string builder interface.

In both cases, I do not think QGIS supports the comments function when creating expressions for filters/queries:

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True, with this way you can save your rules and import / export them ... But it's not as quick as commenting with some symbol at the beginning of the line. Copy / paste in the query Builder is tedious – nebi Jul 17 '14 at 13:58
@nebi, you could always send a request for this to be implemented in future updates. – Joseph Jul 17 '14 at 14:11
Yes, I want to do it – nebi Jul 17 '14 at 14:12

Just as an update to reflect the fast development in QGIS:

In QGIS 2.8.2 (I don't know when it was introduced), commenting in expressions now seems to work!

Using -- for one-line comments and /* ... */ for multi-line comments

turnes the letters to a green color in the expression builder window and they seem indeed to be commented out!

Thanks to the developers!

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Awesome! I don't have QGIS 2.8.2 to test but it is mentioned here so I believe you :) In which case, your answer should be accepted! – Joseph Jun 2 at 12:18
and @Joseph: are you sure you're in the Query Builder? I can't reproduce it. It turns the letters to green but it still doesn't work (2.8.2-Wien). – nebi Jun 4 at 8:11
@nebi - I also cannot reproduce it in the Query Builder (also installed 2.8.2 Wien). Only seems to work in the Field Calculator. Have you opened a ticket (feature request) for this? – Joseph Jun 4 at 11:32
didn't test it beforehand in the Query Builder (sorry) but with rule based rendering expressions etc, cause I hardly ever use that thing. But here it works as well. Am on Linux Mint, maybe there is a difference/bug in Windows? – Bernd V. Jun 4 at 12:22
Ha! Seems I found the difference. I was using it successfully with a Spatialite-Layer. Now I tested it with a ESRI-Shape ... and it fails! – Bernd V. Jun 4 at 12:36

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