content/influxdb3/cloud-dedicated/query-data/sql/basic-query.md
The InfluxDB SQL implementation is powered by the Apache Arrow DataFusion query engine which provides an SQL syntax similar to other relational query languages.
A basic SQL query that queries data from InfluxDB most commonly includes the following clauses:
{{< req type="key" >}}
SELECT: Specify fields, tags, and calculations to output from a
measurement or use the wildcard alias (*) to select all fields and tags
from a measurement.FROM: Specify the measurement to query data from.WHERE: 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 %}}
If at least one row satisfies the query, {{% product-name %}} returns row data in the query result set.
An SQL query result set includes columns listed in the query's SELECT statement.
[!Note]
Sample data
The following examples use the sample data written in the Get started writing data guide. To run the example queries and return results, write the sample data to your {{% product-name %}} database before running the example queries.
SELECT clause to specify what tags and fields to return.
To return all tags and fields, use the wildcard alias (*).FROM clause.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).
SELECT * FROM home WHERE time >= now() - INTERVAL '1 month'
SELECT *
FROM home
WHERE
time >= now() - INTERVAL '7 days'
AND time <= now() - INTERVAL '6 days'
{{% /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 "Query data using a time zone offset" %}}
To query data using a time zone offset, use the
AT TIME ZONE operator
to apply a time zone offset to timestamps in the WHERE clause.
[!Note] Timestamp types in InfluxDB always represent a UTC time.
AT TIME ZONEreturns a UTC timestamp adjusted for the offset of the specified time zone. Timestamps in thetimecolumn are not updated. If you need to display the timestamps in your current timezone, this should be handled client-side.
{{% influxdb/custom-timestamps %}}
SELECT
*
FROM
home
WHERE
time >= '2022-01-01 00:00:00'::TIMESTAMP AT TIME ZONE 'America/Los_Angeles'
AND time <= '2022-01-01 12:00:00'::TIMESTAMP AT TIME ZONE 'America/Los_Angeles'
{{% /influxdb/custom-timestamps %}} {{% /expand %}} {{< /expand-wrapper >}}
To query data without time boundaries, do not include any time-based predicates
in your WHERE clause.
[!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
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
SELECT clause.WHERE clause 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'
SELECT clause, include fields you want to query.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
To alias or rename fields and tags that you query, pass a string literal after
the field or tag identifier in the SELECT clause.
You can use the AS clause to define the alias, but it isn't necessary.
The following queries are functionally the same:
SELECT temp 'temperature', hum 'humidity' FROM home
SELECT temp AS 'temperature', hum AS 'humidity' FROM home