Morphling 
Morphling is a SQL wrapper for database replication topology. Morphling helps you to determine which connection to be used when execute query to the sql database. It's not an ORM
Note : This a modified version version of morphling library with an additional feature. Please refer to the original repo for the original features.
Why you need morphling ?
Golang sql package is allowed you to open multiple connection, but without any restriction, means any connection you
opened, can do all SQL manipulation (select / read, insert, update, delete, select), While slave database supposed to be only allowed to do select , with morphling it manage the master slave connection usage.
Why morphling can only specify one replica ? We can use load balancer such as HAProxy or else to handle a replica set, its provide abstraction to how you want to handle your replica sets load, either round robin or else.
Example
package main
import (
"fmt"
"github.com/cikupin/morphling"
_ "github.com/go-sql-driver/mysql"
)
func main() {
var urlFormat = "%s:%s@tcp(%s:%d)/%s?charset=%s&parseTime=true&loc=Local"
// Prepare data source for master connection
masterUser := "user"
masterPassword := "password"
masterHost := "masterhost"
masterPort := "3306"
masterDBName := "dbname"
masterCharset := "utf8"
dataSourceMaster := fmt.Sprintf(urlFormat, masterUser, masterPassword,masterHost, masterPort, masterDBName, masterCharset)
// Prepare data source for slave connection
slaveUser := "user"
slavePassword := "password"
slaveHost := "slavehost"
slavePort := "3306"
slaveDBName := "dbname"
slaveCharset := "utf8"
dataSourceSlave := fmt.Sprintf(urlFormat, slaveUser, slavePassword,slaveHost, slavePort, slaveDBName, slaveCharset)
// Get database handler
db, err := morphling.OpenConnection(morphling.MySQLDriver, dataSourceMaster, dataSourceSlave)
if err != nil {
panic(fmt.Errorf("failed dial database : %v", err))
}
// Then you can do the query as golang sql package does
var id int
q := fmt.Sprintf("SELECT id FROM accounts LIMIT 1")
err = db.QueryRow(q).Scan(&id)
fmt.Printf(id)
}About
Fun fact, Morphling is a ranged agility dota hero that has many flexible abilities. His ultimate, Morph, transforms him into a copy of an enemy using their stats and basic abilities.
Morphling can be as an analogy of database replication, select / read data is the only basic abilites that replica has,
while select / read, insert, update and delete is the main abilites.