A Trino client for the Go programming language. It enables you to send SQL statements from your Go application to Trino, and receive the resulting data.
- Native Go implementation
- Connections over HTTP or HTTPS
- HTTP Basic and Kerberos authentication
- Per-query user information for access control
- Support custom HTTP client (tunable conn pools, timeouts, TLS)
- Supports conversion from Trino to native Go data types
string,sql.NullStringint64,sql.NullInt64float64,sql.NullFloat64map,trino.NullMaptime.Time,trino.NullTime- Up to 3-dimensional arrays to Go slices, of any supported type
- Go 1.17 or newer
- Trino 372 or newer
You need a working environment with Go installed and $GOPATH set.
Download and install Trino database/sql driver:
go get github.com/trinodb/trino-go-client/trinoMake sure you have Git installed and in your $PATH.
This Trino client is an implementation of Go's database/sql/driver interface. In order to use it, you need to import the package and use the database/sql API then.
Only read operations are supported, such as SHOW and SELECT.
Use trino as driverName and a valid DSN as the dataSourceName.
Example:
import "database/sql"
import _ "github.com/trinodb/trino-go-client/trino"
dsn := "http://user@localhost:8080?catalog=default&schema=test"
db, err := sql.Open("trino", dsn)Both HTTP Basic and Kerberos authentication are supported.
If the DSN contains a password, the client enables HTTP Basic authentication by setting the Authorization header in every request to Trino.
HTTP Basic authentication is only supported on encrypted connections over HTTPS.
This driver supports Kerberos authentication by setting up the Kerberos fields in the Config struct.
Please refer to the Coordinator Kerberos Authentication for server-side configuration.
It's possible to pass user information to Trino, different from the principal used to authenticate to the coordinator. See the System Access Control documentation for details.
In order to pass user information in queries to Trino, you have to add a NamedArg to the query parameters where the key is X-Trino-User. This parameter is used by the driver to inform Trino about the user executing the query regardless of the authentication method for the actual connection, and its value is NOT passed to the query.
Example:
db.Query("SELECT * FROM foobar WHERE id=?", 1, sql.Named("X-Trino-User", string("Alice")))The position of the X-Trino-User NamedArg is irrelevant and does not affect the query in any way.
The Data Source Name is a URL with a mandatory username, and optional query string parameters that are supported by this driver, in the following format:
http[s]://user[:pass]@host[:port][?parameters]
The easiest way to build your DSN is by using the Config.FormatDSN helper function.
The driver supports both HTTP and HTTPS. If you use HTTPS it's recommended that you also provide a custom http.Client that can validate (or skip) the security checks of the server certificate, and/or to configure TLS client authentication.
Parameters are case-sensitive
Refer to the Trino Concepts documentation for more information.
Type: string
Valid values: string describing the source of the connection to Trino
Default: empty
The source parameter is optional, but if used, can help Trino admins troubleshoot queries and trace them back to the original client.
Type: string
Valid values: the name of a catalog configured in the Trino server
Default: empty
The catalog parameter defines the Trino catalog where schemas exist to organize tables.
Type: string
Valid values: the name of an existing schema in the catalog
Default: empty
The schema parameter defines the Trino schema where tables exist. This is also known as namespace in some environments.
Type: string
Valid values: comma-separated list of key=value session properties
Default: empty
The session_properties parameter must contain valid parameters accepted by the Trino server. Run SHOW SESSION in Trino to get the current list.
Type: string
Valid values: the name of a client previously registered to the driver
Default: empty (defaults to http.DefaultClient)
The custom_client parameter allows the use of custom http.Client for the communication with Trino.
Register your custom client in the driver, then refer to it by name in the DSN, on the call to sql.Open:
foobarClient := &http.Client{
Transport: &http.Transport{
Proxy: http.ProxyFromEnvironment,
DialContext: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true,
}).DialContext,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
TLSClientConfig: &tls.Config{
// your config here...
},
},
}
trino.RegisterCustomClient("foobar", foobarClient)
db, err := sql.Open("trino", "https://user@localhost:8080?custom_client=foobar")http://user@localhost:8080?source=hello&catalog=default&schema=foobar
https://user@localhost:8443?session_properties=query_max_run_time=10m,query_priority=2
When passing arguments to queries, the driver supports the following Go data types:
- integers
boolstring- slices
trino.Numeric- a string representation of a numbertime.Time- passed to Trino as a timestamp with a time zone- the result of
trino.Date(year, month, day)- passed to Trino as a date - the result of
trino.Time(hour, minute, second, nanosecond)- passed to Trino as a time without a time zone - the result of
trino.TimeTz(hour, minute, second, nanosecond, location)- passed to Trino as a time with a time zone - the result of
trino.Timestamp(year, month, day, hour, minute, second, nanosecond)- passed to Trino as a timestamp without a time zone
It's not yet possible to pass:
nilfloat32orfloat64bytetime.Durationjson.RawMessage- maps
To use the unsupported types, pass them as strings and use casts in the query, like so:
SELECT * FROM table WHERE col_double = cast(? AS DOUBLE) OR col_timestamp = CAST(? AS TIMESTAMP)When reading response rows, the driver supports most Trino data types, except:
- time and timestamps with precision - all time types are returned as
time.Time. All precisions up to nanoseconds (TIMESTAMP(9)orTIME(9)) are supported (since this is the maximum precision Golang'stime.Timesupports). If a query returns columns defined with a greater precision, values will be trimmed to 9 decimal digits. UseCASTto reduce the returned precision, or convert the value to a string that then can be parsed manually. DECIMAL- returned as stringIPADDRESS- returned as stringINTERVAL YEAR TO MONTHandINTERVAL DAY TO SECOND- returned as stringUUID- returned as string
Data types like HyperLogLog, SetDigest, QDigest, and TDigest are not supported and cannot be returned from a query.
For reading nullable columns, use:
trino.NullTimetrino.NullMap- which stores a map ofmap[string]interface{}or similar structs from thedatabase/sqlpackage, likesql.NullInt64
To read query results containing arrays or maps, pass one of the following structs to the Scan() function:
trino.NullSliceBooltrino.NullSliceStringtrino.NullSliceInt64trino.NullSliceFloat64trino.NullSliceTimetrino.NullSliceMap
For two or three dimensional arrays, use trino.NullSlice2Bool and trino.NullSlice3Bool or equivalents for other data types.
To read ROW values, implement the sql.Scanner interface in a struct. Its Scan() function
will receive a []interface{} slice, with values of the following types:
booljson.Numberfor any numeric Trino types[]interface{}for Trino arraysmap[string]interface{}for Trino mapsstringfor other Trino types, as character, date, time, or timestamp
Apache License V2.0, as described in the LICENSE file.
You can build the client code locally and run tests with the following command:
go test -v -race -timeout 2m ./...
For contributing, development, and release guidelines, see CONTRIBUTING.md.