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

InfluxQL (Influx Query Language) is an SQL-like query language used to interact with InfluxDB and work with times series data.

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

A basic InfluxQL query that queries data from InfluxDB most commonly includes the following clauses:

{{< req type="key" >}}

• {{< req "*">}} SELECT: Specify fields, tags, and calculations to return from a table or use the wildcard alias (*) to select all fields and tags from a table. It requires at least one field key or the wildcard alias (*). For more information, see Notable SELECT statement behaviors.
• {{< req "*">}} FROM: Specify the table to query from. It requires one or more comma-delimited measurement expressions.
• WHERE: Filter data based on field values, tag values, or timestamps. Only return data that meets the specified conditions--for example, falls within a time range, contains specific tag values, or contains a field value outside a specified range.

{{% influxdb/custom-timestamps %}}

SELECT
  temp,
  hum,
  room
FROM home
WHERE
  time >= '2022-01-01T08:00:00Z'
  AND time <= '2022-01-01T20:00:00Z'

{{% /influxdb/custom-timestamps %}}

Result set

If at least one row satisfies the query, {{% product-name %}} returns row data in the query result set. If a query uses a GROUP BY clause, the result set includes the following:

• Columns listed in the query's SELECT clause
• A time column that contains the timestamp for the record or the group
• An iox::measurement column that contains the record's table name
• Columns listed in the query's GROUP BY clause; each row in the result set contains the values used for grouping

GROUP BY result columns

If a query uses GROUP BY and the WHERE clause doesn't filter by time, then groups are based on the default time range.

Basic query examples

• Query data within time boundaries
• Query data without time boundaries
• Query specific fields and tags
• Query fields based on tag values
• Query points based on field values
• Alias queried fields and tags

[!Note]

Sample data

The following examples use the Home sensor data. To run the example queries and return results, write the sample data to your {{% product-name %}} database before running the example queries.

Query data within time boundaries

• Use the SELECT clause to specify what tags and fields to return. Specify at least one field key. To return all tags and fields, use the wildcard alias (*).
• Specify the table to query in the FROM clause.
• Specify time boundaries in the WHERE clause. Include time-based predicates that compare the value of the time column to a timestamp. Use the AND logical operator to chain multiple predicates together.

{{% influxdb/custom-timestamps %}}

SELECT *
FROM home
WHERE
  time >= '2022-01-01T08:00:00Z'
  AND time <= '2022-01-01T12:00:00Z'

{{% /influxdb/custom-timestamps %}}

Query time boundaries can be relative or absolute.

{{< expand-wrapper >}} {{% expand "Query with relative time boundaries" %}}

To query data from relative time boundaries, compare the value of the time column to a timestamp calculated by subtracting an interval from a timestamp. Use now() to return the timestamp for the current time (UTC).

Query all data from the last month

SELECT * FROM home WHERE time >= now() - 30d

Query one day of data from a week ago

SELECT *
FROM home
WHERE
  time >= now() - 7d
  AND time <= now() - 6d

{{% /expand %}}

{{% expand "Query with absolute time boundaries" %}}

To query data from absolute time boundaries, compare the value of the time column to a timestamp literal. Use the AND logical operator to chain together multiple predicates and define both start and stop boundaries for the query.

{{% influxdb/custom-timestamps %}}

SELECT
  *
FROM
  home
WHERE
  time >= '2022-01-01T08:00:00Z'
  AND time <= '2022-01-01T20:00:00Z'

{{% /influxdb/custom-timestamps %}}

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

Query data without time boundaries

To query data without time boundaries, do not include any time-based predicates in your WHERE clause. If a time range is not defined in the WHERE clause, the default time range is the Unix epoch (1970-01-01T00:00:00Z) to now.

[!Warning] Querying data without time bounds can return an unexpected amount of data. The query may take a long time to complete and results may be truncated.

SELECT * FROM home

Query specific fields and tags

To query specific fields, include them in the SELECT clause. If querying multiple fields or tags, comma-delimit each. If a field or tag key includes special characters or spaces or is case-sensitive, wrap the key in double-quotes.

SELECT time, room, temp, hum FROM home

Query fields based on tag values

• In the SELECT clause, include fields you want to query and tags you want to base conditions on.
• In the WHERE clause, include predicates that compare the tag identifier to a string literal. Use logical operators to chain multiple predicates together and apply multiple conditions.

SELECT * FROM home WHERE room = 'Kitchen'

Query points based on field values

• In the SELECT clause, include fields you want to query.
• In the WHERE clause, include predicates that compare the field identifier to a value or expression. Use logical operators (AND, OR) to chain multiple predicates together and apply multiple conditions.

SELECT co, time FROM home WHERE co >= 10 OR co <= -10

Alias queried fields and tags

To alias or rename fields and tags that you query, use the AS clause. After the tag, field, or expression you want to alias, pass AS followed by the alias name as an identifier (wrap in double quotes (") if the alias includes spaces or special characters)--for example:

SELECT temp AS temperature, hum AS "humidity (%)" FROM home

[!Note] When aliasing columns in InfluxQL, use the AS clause and an identifier. When aliasing columns in SQL, you can use the AS clause to define the alias, but it isn't necessary.