Use parameterized queries with InfluxQL
Parameterized queries in InfluxDB Cloud Dedicated let you dynamically and safely change values in a query. If your application code allows user input to customize values or expressions in a query, use a parameterized query to make sure untrusted input is processed strictly as data and not executed as code.
Parameterized queries:
- help prevent injection attacks, which can occur if input is executed as code
- help make queries more reusable
Prevent injection attacks
For more information on security and query parameterization, see the OWASP SQL Injection Prevention Cheat Sheet.
In InfluxDB v3, a parameterized query is an InfluxQL or SQL query that contains one or more named parameter placeholders–variables that represent input data.
- Use parameters in
WHERE
expressions - Parameter data types
- Parameterize an SQL query
- Execute parameterized InfluxQL queries
- Client support for parameterized queries
- Not supported
Parameters only supported in WHERE
expressions
InfluxDB v3 supports parameters in WHERE
clause predicate expressions.
Parameter values must be one of the allowed parameter data types.
If you use parameters in other expressions or clauses,
such as function arguments, SELECT
, or GROUP BY
, then your query might not work as you expect.
Use parameters in WHERE
expressions
You can use parameters in WHERE
clause predicate expressions-–for example, the following query contains a $temp
parameter:
SELECT * FROM measurement WHERE temp > $temp
When executing a query, you specify parameter name-value pairs. The value that you assign to a parameter must be one of the parameter data types.
{"temp": 22.0}
The InfluxDB Querier parses the query text with the parameter placeholders, and then generates query plans that replace the placeholders with the values that you provide. This separation of query structure from input data ensures that input is treated as one of the allowed data types and not as executable code.
Parameter data types
A parameter value can be one of the following data types:
- Null
- Boolean
- Unsigned integer (
u_int64
) - Integer (
int64
) - Double (
float64
) - String
Data type examples
{
"string": "Living Room",
"double": 3.14,
"unsigned_integer": 1234,
"integer": -1234,
"boolean": false,
"null": Null,
}
Time expressions
To parameterize time bounds, substitute a parameter for a timestamp literal–for example:
SELECT *
FROM home
WHERE time >= $min_time
For the parameter value, specify the timestamp literal as a string–for example:
InfluxDB executes the query as the following:
Not compatible with parameters
If you use parameters for the following, your query might not work as you expect:
- In clauses other than
WHERE
, such asSELECT
orGROUP BY
- As function arguments, such as
avg($temp)
- In place of identifiers, such as column or table names
- In place of duration literals, such as
time > now() - $min_duration
Parameterize an SQL query
Sample data
The following examples use the Get started home sensor data. To run the example queries and return results, write the sample data to your InfluxDB Cloud Dedicated database before running the example queries.
To use a parameterized query, do the following:
In your query text, use the
$parameter
syntax to reference a parameter name–for example, the following query contains$room
and$min_temp
parameter placeholders:SELECT * FROM home WHERE time > now() - 7d AND temp >= $min_temp AND room = $room
Provide a value for each parameter name. If you don’t assign a value for a parameter, InfluxDB returns an error. The syntax for providing parameter values depends on the client you use–for example:
// Define a QueryParameters struct--a map of parameters to input values. parameters := influxdb3.QueryParameters{ "room": "Kitchen", "min_temp": 20.0, }
After InfluxDB receives your request and parses the query, it executes the query as
SELECT *
FROM home
WHERE time > now() - 7d
AND temp >= 20.0
AND room = 'Kitchen'
Execute parameterized InfluxQL queries
Sample data
The following examples use the Get started home sensor data. To run the example queries and return results, write the sample data to your InfluxDB Cloud Dedicated database before running the example queries.
Use InfluxDB Flight RPC clients
Using the InfluxDB v3 native Flight RPC protocol and supported clients, you can send a parameterized query and a list of parameter name-value pairs.
InfluxDB Flight clients that support parameterized queries pass the parameter name-value pairs in a Flight ticket params
field.
The following examples show how to use client libraries to execute parameterized InfluxQL queries:
import (
"context"
"fmt"
"io"
"os"
"text/tabwriter"
"time"
"github.com/apache/arrow/go/v14/arrow"
"github.com/InfluxCommunity/influxdb3-go/influxdb3"
)
func Query(query string, parameters influxdb3.QueryParameters,
options influxdb3.QueryOptions) error {
url := os.Getenv("INFLUX_HOST")
token := os.Getenv("INFLUX_TOKEN")
database := os.Getenv("INFLUX_DATABASE")
// Instantiate the influxdb3 client.
client, err := influxdb3.New(influxdb3.ClientConfig{
Host: url,
Token: token,
Database: database,
})
if err != nil {
panic(err)
}
// Ensure the client is closed after the Query function finishes.
defer func(client *influxdb3.Client) {
err := client.Close()
if err != nil {
panic(err)
}
}(client)
// Call the client's QueryWithParameters function.
// Provide the query, parameters, and the InfluxQL QueryType option.
iterator, err := client.QueryWithParameters(context.Background(), query,
parameters, influxdb3.WithQueryType(options.QueryType))
// Create a buffer for storing rows as you process them.
w := tabwriter.NewWriter(io.Discard, 4, 4, 1, ' ', 0)
w.Init(os.Stdout, 0, 8, 0, '\t', 0)
fmt.Fprintf(w, "time\troom\tco\thum\ttemp\n")
// Format and write each row to the buffer.
// Process each row as key-value pairs.
for iterator.Next() {
row := iterator.Value()
// Use Go arrow and time packages to format unix timestamp
// as a time with timezone layout (RFC3339 format)
time := (row["time"].(arrow.Timestamp)).
ToTime(arrow.Nanosecond).Format(time.RFC3339)
fmt.Fprintf(w, "%s\t%s\t%d\t%.1f\t%.1f\n",
time, row["room"], row["co"], row["hum"], row["temp"])
}
w.Flush()
return nil
}
func main() {
// Use the $placeholder syntax in a query to reference parameter placeholders
// for input data.
// The following InfluxQL query contains the placeholders $room and $min_temp.
query := `
SELECT *
FROM home
WHERE time > now() - 7d
AND temp >= $min_temp
AND room = $room`
// Define a QueryParameters struct--a map of placeholder names to input values.
parameters := influxdb3.QueryParameters{
"room": "Kitchen",
"min_temp": 20.0,
}
Query(query, parameters, influxdb3.QueryOptions{
QueryType: influxdb3.InfluxQL,
})
}
Client support for parameterized queries
- Not all InfluxDB v3 Flight clients support parameterized queries.
- InfluxDB doesn’t currently support parameterized queries or DataFusion prepared statements for Flight SQL or Flight SQL clients.
- InfluxDB v3 SQL and InfluxQL parameterized queries aren’t supported in InfluxDB v1 and v2 clients.
Not supported
Currently, parameterized queries in InfluxDB Cloud Dedicated don’t provide the following:
- support for DataFusion prepared statements
- query caching, optimization, or performance benefits
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