sql

Documentation

Overview

Package sql provides functions to trace the database/sql package (https://golang.org/pkg/database/sql). It will automatically augment operations such as connections, statements and transactions with tracing.

We start by telling the package which driver we will be using. For example, if we are using "github.com/lib/pq", we would do as follows:

sqltrace.Register("pq", pq.Driver{})
db, err := sqltrace.Open("pq", "postgres://pqgotest:password@localhost...")

The rest of our application would continue as usual, but with tracing enabled.

Example

package main

import (
	"log"

	sqltrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/database/sql"

	"github.com/lib/pq"
)

func main() {
	// The first step is to register the driver that we will be using.
	sqltrace.Register("postgres", &pq.Driver{})

	// Followed by a call to Open.
	db, err := sqltrace.Open("postgres", "postgres://pqgotest:password@localhost/pqgotest?sslmode=disable")
	if err != nil {
		log.Fatal(err)
	}

	// Then, we continue using the database/sql package as we normally would, with tracing.
	rows, err := db.Query("SELECT name FROM users WHERE age=?", 27)
	if err != nil {
		log.Fatal(err)
	}
	defer rows.Close()
}

Example (Context)

package main

import (
	"context"
	"log"

	sqltrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/database/sql"
	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/ext"
	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"

	"github.com/go-sql-driver/mysql"
)

func main() {
	// Register the driver that we will be using (in this case mysql) under a custom service name.
	sqltrace.Register("mysql", &mysql.MySQLDriver{}, sqltrace.WithServiceName("my-db"))

	// Open a connection to the DB using the driver we've just registered with tracing.
	db, err := sqltrace.Open("mysql", "user:password@/dbname")
	if err != nil {
		log.Fatal(err)
	}

	// Create a root span, giving name, server and resource.
	_, ctx := tracer.StartSpanFromContext(context.Background(), "my-query",
		tracer.SpanType(ext.SpanTypeSQL),
		tracer.ServiceName("my-db"),
		tracer.ResourceName("initial-access"),
	)

	// Subsequent spans inherit their parent from context.
	rows, err := db.QueryContext(ctx, "SELECT * FROM city LIMIT 5")
	if err != nil {
		log.Fatal(err)
	}
	rows.Close()
}

Example (Sqlite)

package main

import (
	"context"
	"log"

	sqlite "github.com/mattn/go-sqlite3"
	sqltrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/database/sql"
	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
)

func main() {
	// Register the driver that we will be using (in this case Sqlite) under a custom service name.
	sqltrace.Register("sqlite", &sqlite.SQLiteDriver{}, sqltrace.WithServiceName("sqlite-example"))

	// Open a connection to the DB using the driver we've just registered with tracing.
	db, err := sqltrace.Open("sqlite", "./test.db")
	if err != nil {
		log.Fatal(err)
	}

	// Create a root span, giving name, server and resource.
	_, ctx := tracer.StartSpanFromContext(context.Background(), "my-query",
		tracer.SpanType("example"),
		tracer.ServiceName("sqlite-example"),
		tracer.ResourceName("initial-access"),
	)

	// Subsequent spans inherit their parent from context.
	rows, err := db.QueryContext(ctx, "SELECT * FROM city LIMIT 5")
	if err != nil {
		log.Fatal(err)
	}
	rows.Close()
}

Index

• func Open(driverName, dataSourceName string) (*sql.DB, error)
• func Register(driverName string, driver driver.Driver, opts ...RegisterOption)
• type RegisterOption
  • func WithAnalytics(on bool) RegisterOption
  • func WithAnalyticsRate(rate float64) RegisterOption
  • func WithServiceName(name string) RegisterOption

Examples

• Package
• Package (Context)
• Package (Sqlite)

Functions

func Open

func Open(driverName, dataSourceName string) (*sql.DB, error)

Open returns connection to a DB using a the traced version of the given driver. In order for Open to work, the driver must first be registered using Register or RegisterWithServiceName. If this did not occur, Open will return an error.

func Register

func Register(driverName string, driver driver.Driver, opts ...RegisterOption)

Register tells the sql integration package about the driver that we will be tracing. It must be called before Open, if that connection is to be traced. It uses the driverName suffixed with ".db" as the default service name.

Types

type RegisterOption

type RegisterOption func(*registerConfig)

RegisterOption represents an option that can be passed to Register.

func WithAnalytics

func WithAnalytics(on bool) RegisterOption

WithAnalytics enables Trace Analytics for all started spans.

func WithAnalyticsRate

func WithAnalyticsRate(rate float64) RegisterOption

WithAnalyticsRate sets the sampling rate for Trace Analytics events correlated to started spans.

func WithServiceName

func WithServiceName(name string) RegisterOption

WithServiceName sets the given service name for the registered driver.