SELECT in Riak TS
You can use the SELECT statement in Riak TS to query your TS dataset. This document will show you how to run various queries using SELECT
.
- See the guidelines for more information on limitations and rules for queries in TS.
- See aggregate functions to learn how turn a set of rows in your Riak TS table into a value.
- See arithmetic operations to see a list of operations available with
SELECT
. - See GROUP BY to learn how to condense rows sharing the same value.
For all of the examples on this page, we are using our standard example GeoCheckin table:
CREATE TABLE GeoCheckin
(
region VARCHAR NOT NULL,
state VARCHAR NOT NULL,
time TIMESTAMP NOT NULL,
weather VARCHAR NOT NULL,
temperature DOUBLE,
PRIMARY KEY (
(region, state, QUANTUM(time, 15, 'm')),
region, state, time
)
)
When querying with user-supplied data, it is essential that you protect against SQL injection. Please verify the user-supplied data before constructing queries.
Querying Columns
All queries using SELECT
must include a ‘where’ clause with all components.
You can select particular columns from the data to query:
select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina'
Client-specific examples:
String queryText = "select weather, temperature from GeoCheckin " +
"where time > 1234560 and time < 1234569 and " +
"region = 'South Atlantic' and state = 'South Carolina'";
Query query = new Query.Builder(queryText).build();
QueryResult queryResult = client.execute(query);
Riak::Timeseries::Query.new(client, "select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina'").issue!
fmt = """
select weather, temperature from GeoCheckin where
time > {t1} and time < {t2} and
region = 'South Atlantic' and state = 'South Carolina'
"""
query = fmt.format(t1=tenMinsAgoMsec, t2=nowMsec)
ts_obj = client.ts_query('GeoCheckin', query)
var now = DateTime.UtcNow;
var tenMinsAgo = now.AddMinutes(-10);
var qfmt = "SELECT * FROM GeoCheckin WHERE time > {0} and time < {1} and region = 'South Atlantic' and state = 'South Carolina'";
var q = string.Format(
qfmt,
DateTimeUtil.ToUnixTimeMillis(tenMinsAgo),
DateTimeUtil.ToUnixTimeMillis(now));
var cmd = new Query.Builder()
.WithTable("GeoCheckin")
.WithQuery(q)
.Build();
RiakResult rslt = client.Execute(cmd);
var callback = function(err, resp) {
// resp.rows and resp.columns
// have data
};
// NB: t1/t2 are integers representing unix timestamps with
// millisecond resolution
var queryText = "select * from GeoCheckin where time > " + t1 +
" and time < " + t2 +
" and region = 'South Atlantic' and state = 'South Carolina'";
var q = new Riak.Commands.TS.Query.Builder()
.withQuery(queryText)
.withCallback(callback)
.build();
cluster.execute(q);
riakc_ts:query(Pid, "select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina'").
$response = (new Command\Builder\TimeSeries\Query($riak))
->withQuery("select weather, temperature from GeoCheckin where region = 'South Atlantic' and state = 'state1' and time > 1234560 and time < 1234569")
->build()
->execute();
cmd, err := riak.NewTsQueryCommandBuilder()
.WithQuery("select weather, temperature from GeoCheckin where region = 'South Atlantic' and state = 'state1' and time > 1234560 and time < 1234569")
.Build()
if err != nil {
return err
}
err = cluster.Execute(cmd)
Extended Queries
You can extend the query beyond the primary key and use secondary columns to filter results. In this example, we are extending our query to filter based on temperature
:
select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina' and temperature > 27.0
Client-specific examples:
String queryText = "select weather, temperature from GeoCheckin " +
"where time > 1234560 and time < 1234569 and " +
"region = 'South Atlantic' and state = 'South Carolina' " +
"temperature > 27.0";
Query query = new Query.Builder(queryText).build();
QueryResult queryResult = client.execute(query);
Riak::Timeseries::Query.new(client, "select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina' and temperature > 27.0").issue!
fmt = """
select weather, temperature from GeoCheckin where
time > {t1} and time < {t2} and
region = 'South Atlantic' and state = 'South Carolina' and
temperature > 27.0
"""
query = fmt.format(t1=tenMinsAgoMsec, t2=nowMsec)
ts_obj = client.ts_query('GeoCheckin', query)
var now = DateTime.UtcNow;
var tenMinsAgo = now.AddMinutes(-10);
var qfmt = "SELECT weather, temperature FROM GeoCheckin WHERE time > {0} and time < {1} and region = 'South Atlantic' and state = 'South Carolina' and temperature > 27.0";
var q = string.Format(
qfmt,
DateTimeUtil.ToUnixTimeMillis(tenMinsAgo),
DateTimeUtil.ToUnixTimeMillis(now));
var cmd = new Query.Builder()
.WithTable("GeoCheckin")
.WithQuery(q)
.Build();
RiakResult rslt = client.Execute(cmd);
var callback = function(err, resp) {
// resp.rows and resp.columns
// have data
};
// NB: t1/t2 are integers representing unix timestamps with
// millisecond resolution
var queryText = "select weather, temperature from GeoCheckin where time > " + t1 +
" and time < " + t2 +
" and region = 'South Atlantic' and state = 'South Carolina'" +
" and temperature > 27.0";
var q = new Riak.Commands.TS.Query.Builder()
.withQuery(queryText)
.withCallback(callback)
.build();
cluster.execute(q);
riakc_ts:query(Pid, "select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina' and temperature > 27.0").
$response = (new Command\Builder\TimeSeries\Query($riak))
->withQuery("select weather, temperature from GeoCheckin where region = 'South Atlantic' and state = 'state1' and time > 1234560 and time < 1234569 and temperature > 27.0")
->build()
->execute();
cmd, err := riak.NewTsQueryCommandBuilder()
.WithQuery("select weather, temperature from GeoCheckin where region = 'South Atlantic' and state = 'state1' and time > 1234560 and time < 1234569 and temperature > 27.0")
.Build()
if err != nil {
return err
}
err = cluster.Execute(cmd)
You can also use or
when querying against column values, such as temperature
in our example. Note that the parentheses are required:
select weather, temperature from GeoCheckin where time > 1234560 and time < 1234569 and region = 'South Atlantic' and state = 'South Carolina' and (temperature > 27.0 or temperature < 0.0)
You cannot use or
between two complete clauses, since keys cannot be specified twice.
ISO 8601
It is possible to use ISO 8601-compliant date/time strings in SELECT statements instead of integer timestamps:
time > '2015-12-11 20:04:37' and time < '2015-12-11 20:04:50'
You cannot use reduced accuracy time representations. Instead, you must specify your time down to the second (or use fractional times).
ISO 8601 time strings are converted to a millisecond timestamp, which the query then uses.
select weather, temperature from GeoCheckin where time > '2009-11-01 03:15:00+07' and time < '2009-11-01 03:45:00+07' and region = 'South Atlantic' and state = 'South Carolina'
The timestamps used inside Riak TS for those comparisons will be 1257020100000 and 1257021900000.
The same query, expressed with fractional time:
select weather, temperature from GeoCheckin where time > '2009-11-01 03.25+07' and time < '2009-11-01 03.75+07' and region = 'South Atlantic' and state = 'South Carolina'
See our documentation on ISO 8601 support for more details on how to use ISO 8601.