docs-v2/content/shared/influxdb3-query-guides/influxql/explore-schema.md

Use InfluxQL SHOW statements to return information about your data schema.

{{% influxql/v1-v3-data-model-note %}}

• List measurements in a database
  • List measurements that contain specific tag key-value pairs
  • List measurements that match a regular expression
• List field keys in a measurement
• List tag keys in a measurement
  • List tag keys in measurements that contain a specific tag key-value pair
• List tag values for a specific tag key
  • List tag values for multiple tags
  • List tag values for tags that match a regular expression
  • List tag values associated with a specific tag key-value pair

[!Note]

Sample data

The following examples use data provided in sample data sets. To run the example queries and return identical results, follow the instructions provided for each sample data set to write the data to your {{% product-name %}} database.

List measurements in a database

Use SHOW MEASUREMENTS to list measurements in your InfluxDB database.

SHOW MEASUREMENTS

{{< expand-wrapper >}} {{% expand "View example output" %}}

{{% influxql/table-meta %}} name: measurements {{% /influxql/table-meta %}}

name
bitcoin
home
home_actions
numbers
weather

{{% /expand %}} {{< /expand-wrapper >}}

List measurements that contain specific tag key-value pairs

To return only measurements with specific tag key-value pairs, include a WHERE clause with tag key-value pairs to query for.

SHOW MEASUREMENTS WHERE room = 'Kitchen'

{{< expand-wrapper >}} {{% expand "View example output" "1" %}}

{{% influxql/table-meta %}} name: measurements {{% /influxql/table-meta %}}

name
home
home_actions

{{% /expand %}} {{< /expand-wrapper >}}

List measurements that match a regular expression

To return only measurements with names that match a regular expression, include a WITH clause that compares the MEASUREMENT to a regular expression.

SHOW MEASUREMENTS WITH MEASUREMENT =~ /^home/

{{< expand-wrapper >}} {{% expand "View example output" "2" %}}

{{% influxql/table-meta %}} name: measurements {{% /influxql/table-meta %}}

name
home
home_actions

{{% /expand %}} {{< /expand-wrapper >}}

List field keys in a measurement

Use SHOW FIELD KEYS to return all field keys in a measurement. Include a FROM clause to specify the measurement. If no measurement is specified, the query returns all field keys in the database.

SHOW FIELD KEYS FROM home

{{< expand-wrapper >}} {{% expand "View example output" "3" %}}

{{% influxql/table-meta %}} name: home {{% /influxql/table-meta %}}

fieldKey	fieldType
co	integer
hum	float
temp	float

{{% /expand %}} {{< /expand-wrapper >}}

List tag keys in a measurement

Use SHOW TAG KEYS to return all tag keys in a measurement. Include a FROM clause to specify the measurement. If no measurement is specified, the query returns all tag keys in the database.

SHOW TAG KEYS FROM home_actions

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{{% influxql/table-meta %}} name: home_actions {{% /influxql/table-meta %}}

tagKey
action
level
room

{{% /expand %}} {{< /expand-wrapper >}}

List tag keys in measurements that contain a specific tag key-value pair

To return all tag keys measurements that contain specific tag key-value pairs, include a WHERE clause with the tag key-value pairs to query for.

SHOW TAG KEYS WHERE room = 'Kitchen'

{{< expand-wrapper >}} {{% expand "View example output" "5" %}}

{{% influxql/table-meta %}} name: home {{% /influxql/table-meta %}}

tagKey
room

{{% influxql/table-meta %}} name: home_actions {{% /influxql/table-meta %}}

tagKey
action
level
room

{{% /expand %}} {{< /expand-wrapper >}}

List tag values for a specific tag key

Use SHOW TAG VALUES to return all values for specific tags in a measurement.

• Include a FROM clause to specify one or more measurements to query.
• Use the WITH clause to compare KEY to tag keys to list the values of.
• Use the WHERE clause to restrict the search to a specific time range (default time range is the last day).

SHOW TAG VALUES FROM weather WITH KEY = location

[!Note]

Include a FROM clause

We strongly recommend including a FROM clause with the SHOW TAG VALUES statement that specifies 1-50 tables to query. Without a FROM clause, the InfluxDB query engine must read data from all tables and return unique tag values from each.

Depending on the number of tables in your database and the number of unique tag values in each table, excluding a FROM clause can result in poor query performance, query timeouts, or unnecessary resource allocation that may affect other queries.

{{< expand-wrapper >}} {{% expand "View example output" "5" %}}

{{% influxql/table-meta %}} name: weather {{% /influxql/table-meta %}}

key	value
location	Concord
location	Hayward
location	San Francisco

{{% /expand %}} {{< /expand-wrapper >}}

List tag values for multiple tags

To return tag values for multiple specific tag keys, use the IN operator in the WITH clause to compare KEY to a list of tag keys.

SHOW TAG VALUES FROM home_actions WITH KEY IN ("level", "action")

{{< expand-wrapper >}} {{% expand "View example output" "6" %}}

{{% influxql/table-meta %}} name: home_actions {{% /influxql/table-meta %}}

key	value
action	alert
action	cool
level	ok
level	warn

{{% /expand %}} {{< /expand-wrapper >}}

List tag values for tags that match a regular expression

To return only tag values from tags keys that match a regular expression, use regular expression comparison operators in your WITH clause to compare KEY to the regular expression.

SHOW TAG VALUES FROM home, home_actions WITH KEY =~ /oo/

{{< expand-wrapper >}} {{% expand "View example output" "7" %}}

{{% influxql/table-meta %}} name: home {{% /influxql/table-meta %}}

key	value
room	Kitchen
room	Living Room

{{% influxql/table-meta %}} name: home_actions {{% /influxql/table-meta %}}

key	value
room	Kitchen
room	Living Room

{{% /expand %}} {{< /expand-wrapper >}}

List tag values associated with a specific tag key-value pair

To list tag values for tags associated with a specific tag key-value pair:

• Use the WITH clause to identify what tag keys to return values for.
• Include a WHERE clause that identifies the tag key-value pair to query for.

The following example returns tag values for the action and level tags for points where the room tag value is Kitchen.

SHOW TAG VALUES FROM home_actions WITH KEY IN ("action", "level") WHERE room = 'Kitchen'

{{< expand-wrapper >}} {{% expand "View example output" "8" %}}

{{% influxql/table-meta %}} name: home_actions {{% /influxql/table-meta %}}

key	value
action	alert
action	cool
level	ok
level	warn

{{% /expand %}} {{< /expand-wrapper >}}