Can't Figure out how to use GORM's DBResolver

Question

import (
    "github.com/jinzhu/gorm"
    _ "github.com/jinzhu/gorm/dialects/mysql"
    "server/config"
    "gorm.io/plugin/dbresolver"
)
    
func DB(config *config.Config) {
    var err error

    config.DB, err = gorm.Open("mysql", config.DBDSN)
    if err != nil {
        panic(err)
    }


    if !config.IsDev {
        config.DB.Use(dbresolver.Register(dbresolver.Config{
            Replicas: []gorm.Dialector{mysql.Open("mysql", config.DBDSN2)},
        }))
    }

}

I am trying to use GORM's DBresolver to make use of my cloud SQL instance's read replica. I think there is some versioning issue with the GORM package that I use and the DBresolver plugin. When I run the code above I get the following error:

config.DB.Use undefined (type *"github.com/jinzhu/gorm".DB has no field or method Use)
undefined: "github.com/jinzhu/gorm".Dialect

I could not find any reason for this online and there are very few online resources on GORM's advanced functionalities. I can easily get the replica to work if I create a separate connection to it, but that way I need to specify the DB every-time I interact with the database. I used the following to implement the code above: https://gorm.io/docs/dbresolver.html

Ezequiel Muns Ezequiel Muns · Accepted Answer · 2021-03-07T17:44:40

You are using the v1 import path for gorm, but DBResolver is a V2 feature. You'll want instead to use:

"gorm.io/gorm" for the main import package
"gorm.io/driver/mysql" for the driver import
gorm.Open with mysql.Open for creating the connections.
V2 is mostly backwards compatible, but you'll need to make sure any old code is tested to work on the new version.

import (
    "gorm.io/gorm"
    "gorm.io/driver/mysql"
    "gorm.io/plugin/dbresolver"
    "server/config"
)
    
func DB(config *config.Config) {
    var err error

    config.DB, err := gorm.Open(mysql.Open(config.DBDSN), &gorm.Config{})
    if err != nil {
        panic(err)
    }


    if !config.IsDev {
        config.DB.Use(dbresolver.Register(dbresolver.Config{
            Replicas: []gorm.Dialector{mysql.Open("mysql", config.DBDSN2)},
        }))
    }
}

Can't Figure out how to use GORM's DBResolver

1 Answers