Feature request: Add support for template variables in query builder

[sunker]

Currently, the azure data explorer query editor only has full support for template variables while using the code editor. Using a template variable in the query builder might work for some fields, but in some cases it won't. Here are some examples of where it doesn't work:

• When you want to filter on a numeric field and use a variable in the value field. The current data model only allows you to store numeric values, so strings (template variables) are not accept and evaluates to 0.
  
• When you want to filter on a string field and use a variable in the value field. Currently this only works if the template variable value is surrounded by single quotes.

[sarahzinger]

Just a heads up: I was recently looking at this and it seems to me that we do (at least sometimes) support using strings for where values, but I had trouble using it for the column names for where filters:


I'm not sure if this is a difference in the creation of the template variables maybe? I used the "custom" type for these. The main problem is that the == is not showing up

@sunker what do you think about turning this into an issue again? It sounds like this is more bug than feature request

[andresmgot]

sounds good to treat this as an issue. But we already have one?

[sunker]

@sarahzinger are the values in your custom variable wrapped in single quotes? I faced this problem when using template variable queries that returned strings, yet they were not escaped as strings when expanded in the builder. Feel like that should be possible to solve using a variable pattern such as ${myVariable:singlequote} though.

The initial problem that caused me to raise a feature request for this was the usage of variables in numeric fields. I tested this is a few old versions of ADX, and it doesn't seem like this was ever supported. At the same time, it didn't seem like there were any easy ways of adding support for this. If this is something we can add support for in the near future, I don't mind converting it to an issue.

[sarahzinger]

@andresmgot ah yeah I guess I was thinking this was sort of a related but maybe separate larger feature request to add better support for template variables, as this issue also encompasses dealing with non-numeric values, but I suppose we can just keep the issue we have.

@sunker I used double quotes I'm not sure if that is the difference?

[sunker]

@sunker I used double quotes I'm not sure if that is the difference?

Yeah actually double quotes should work. Think this should work for template variable queries returning strings as long as they use the correct pattern, i.e ${myVariable:doublequote}

[andresmgot]

As far as I can tell, this discussion gather 3 requests:

• Be able to use template variables for columns other than strings (e.g. number or booleans)
• Be able to use template variables as keys for filters (e.g. | where $myVariable === "foo")
• Automatically quote variables when targetting strings. This can be workaround-ed manually adding the quotes to the possible values in the variable.