戈朗-迁移找不到postgres的司机

Question

在我的internal/platform/database/database.go里

import (
    "github.com/golang-migrate/migrate"
    "github.com/jmoiron/sqlx"
    _ "github.com/lib/pq"
)

func RunMigrations() error {
    m, err := migrate.New(
        "file://schema",
        "postgres://postgres:postgres@localhost:5432/postgres?sslmode=disable")
    if err != nil {
        return errors.Wrap(err, "error creating migrations object")
    }

这个函数是从我的cmd/my-api/main.go调用的，如下所示：

import (
    _ "github.com/golang-migrate/migrate/v4/database/postgres"
    _ "github.com/golang-migrate/migrate/v4/source/file"
    "github.com/jmoiron/sqlx"
    _ "github.com/lib/pq"
    "github.com/myrepo/myproject/internal/platform/database"
)

    // =========================================================================
    // Executing migrations
    if err := database.RunMigrations(); err != nil {
        log.Fatal(err)
    }

虽然我是在中导入驱动程序-两个文件，_ "github.com/lib/pq"

运行程序失败如下：

error creating migrations object: source driver: unknown driver file (forgotten import?)
exit status 1

为什么会这样呢？

Answer 1

golang-migrate似乎需要它自己版本的相应驱动程序(?)

下面的输入帮我解决了这个问题

_ "github.com/golang-migrate/migrate/v4/database/postgres"

Answer 2

导入以下内容时，将触发postgres驱动程序init函数，此函数将注册postgres驱动程序。

_ "github.com/golang-migrate/migrate/v4/database/postgres"

你可以检查这个。https://www.calhoun.io/why-we-import-sql-drivers-with-the-blank-identifier/