I'm still getting empty result: SELECT "host", "value" FROM mem WHERE time < now() - 2m
Success! (no results to display) My goal is to count number of hosts and get this number into Grafana. On Tuesday, September 27, 2016 at 6:41:30 PM UTC+3, Sean Beckett wrote: > > That is because "host" is a tag > <https://docs.influxdata.com/influxdb/v1.0/concepts/glossary/#tag>, not a > field <https://docs.influxdata.com/influxdb/v1.0/concepts/glossary/#field>. > SELECT statements must include at least one field. > > If you want only the values of "host", that's a SHOW > <https://docs.influxdata.com/influxdb/v1.0/query_language/schema_exploration/#explore-tag-values-with-show-tag-values> > > query, not a SELECT > <https://docs.influxdata.com/influxdb/v1.0/query_language/data_exploration/#the-select-statement-and-the-where-clause> > > query: > > SHOW TAG VALUES FROM mem_usage_percent WITH KEY = "host" > > Note that the SHOW query does not accept a "WHERE time" clause. To get > hosts during a particular time, use a SELECT query with a field as well: > > SELECT "host", "value" FROM mem_usage_percent WHERE time > ... > > > > On Tue, Sep 27, 2016 at 12:04 AM, Paul Letskii <[email protected] > <javascript:>> wrote: > >> Ok. But how have I change this query: "SELECT "host" FROM >> "mem_usage_percent"" to get just hosts field? >> According to documentation it is correct query ( >> https://docs.influxdata.com/influxdb/v1.0/query_language/data_exploration/#the-select-statement-and-the-where-clause >> ) >> >> >> On Monday, September 26, 2016 at 6:00:06 PM UTC+3, Sean Beckett wrote: >>> >>> Every SELECT statement must have at least one field. You selecting only >>> a tag. Use either "SHOW TAG VALUES" or include a field in the query. >>> >>> On Mon, Sep 26, 2016 at 6:55 AM, Paul Letskii <[email protected]> wrote: >>> >>>> Hi all! >>>> >>>> InfluxDB version 1.0\ >>>> >>>> I'm trying to get list of hosts from measurement "mem_usage_percent". >>>> >>>> This query works: >>>> SELECT * FROM "mem_usage_percent" >>>> >>>> This one doesn't: >>>> SELECT "host" FROM "mem_usage_percent" >>>> Accordingly to documentation it has to. >>>> >>>> My final goal is to count number of unique hosts. Like: SELECT >>>> count("host") FROM "mem_usage_percent" >>>> >>>> What is correct syntax to get information from certain field? >>>> >>>> Thank you in advance! >>>> >>>> Best regards, >>>> Paul Letskii >>>> >>>> -- >>>> Remember to include the InfluxDB version number with all issue reports >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "InfluxDB" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/influxdb. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/influxdb/f3c71013-7e8c-4fdb-9808-0b1fb35e9052%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/influxdb/f3c71013-7e8c-4fdb-9808-0b1fb35e9052%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> >>> >>> -- >>> Sean Beckett >>> Director of Support and Professional Services >>> InfluxDB >>> >> -- >> Remember to include the InfluxDB version number with all issue reports >> --- >> You received this message because you are subscribed to the Google Groups >> "InfluxDB" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at https://groups.google.com/group/influxdb. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/influxdb/215c75a2-3837-4c60-b5bd-14bb26f74fbe%40googlegroups.com >> >> <https://groups.google.com/d/msgid/influxdb/215c75a2-3837-4c60-b5bd-14bb26f74fbe%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Sean Beckett > Director of Support and Professional Services > InfluxDB > -- Remember to include the InfluxDB version number with all issue reports --- You received this message because you are subscribed to the Google Groups "InfluxDB" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/influxdb. To view this discussion on the web visit https://groups.google.com/d/msgid/influxdb/38bc648d-1930-47ee-bef9-62112bba5a00%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
