go - What does an underscore in front of an import statement mean?

Question

I saw this example from sqlite3 on GitHub :

import (
        "database/sql"
        "fmt"
        _ "github.com/mattn/go-sqlite3"
        "log"
        "os"
)

and cannot seem to find what the underscore in front of an import statement means.

Answer 1

Waitting for answers