PostgreSQL: __unixEpochGroup to support arithmetic expression as argument

[s0nik42]

Following macro call generates wrong expression :

$__unixEpochGroupAlias(height+42,$__interval)

=> floor(height+42/60)*60 AS "time"

instead of

=> floor((height+42)/60)*60 AS "time"

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

[zoltanbedi]

Hi @s0nik42,
Thanks for fixing this. Can you please update the failing test and add your use case to it?

[s0nik42]

@zoltanbedi sure, just not familiar doing that, can you point me to the test file? I will do the modification

[zoltanbedi]

zoltanbedi sure, just not familiar doing that, can you point me to the test file? I will do the modification

@s0nik42 I'd change this line https://github.com/grafana/grafana/blob/main/pkg/tsdb/postgres/macros_test.go#L140
"SELECT $__unixEpochGroup(time_column + 1,'5m')" and then we have to change the expected output in here https://github.com/grafana/grafana/blob/main/pkg/tsdb/postgres/macros_test.go#L144

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[s0nik42]

@zoltanbedi made the change hope I did it well. One question for my future commit how can I run a specific test to verify everything works before committing ?

[zoltanbedi]

zoltanbedi made the change hope I did it well. One question for my future commit how can I run a specific test to verify everything works before committing ?

go test -v -run <regexp> would match on test name, as far as I know.

[zoltanbedi]

Thank you @s0nik42!