(GoLang) panic: sql: Register called twice for driver postgres - postgresql

Question

I have probably spent way to much time on this, so I decided to try here.
I'm having trouble figuring out why my Register is being called twice?
Best I can figure, it seems to be calling once at sql.Register() and again at sqlx.Connect(). But if I remove the sql.Register(), then theres no drivers.
Honestly, I am pretty new to GoLang, I'm hoping for any sort of direction here.
Code - w/o sql.Register
package main
import (
"fmt"
"database/sql"
"github.com/jmoiron/sqlx"
)
const (
host = "localhost"
port = 5432
user = "postgres"
password = "password"
dbname = "sampledb"
)
/*-------------------------------------------*\
|| Functions ||
\*-------------------------------------------*/
// Error Checking Fn
func CheckError(err error, str string) {
if err != nil {
fmt.Printf("Error # : %s\n", str)
panic(err)
}
}
/*-------------------------------------------*\
|| Main() ||
\*-------------------------------------------*/
func main() {
// Open DB Conn
psqlconn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable", host, port, user, password, dbname)
// sql.Register("postgres", &pq.Driver{})
fmt.Printf(":: Drivers ::\n%s\n", sql.Drivers())
db, err := sqlx.Connect("postgres", psqlconn)
CheckError(err, "Main: sqlx.connect")
defer db.Close()
}
Error - w/o sql.Register
$ go run name-generator.go
:: Drivers ::
[]
Error # : Main: sqlx.connect
panic: sql: unknown driver "postgres" (forgotten import?)
goroutine 1 [running]:
main.CheckError({0xc84320, 0xc000056680}, {0xc6073f, 0x5})
C:/path/to/program.go:26 +0xa7 <--- Func CheckError(): panic(err)
main.main()
C:/path/to/program.go:40 +0x125 <--- Func Main(): CheckError()
exit status 2
Code - w/ sql.Register
package main
import (
"fmt"
"database/sql"
"github.com/jmoiron/sqlx"
"github.com/lib/pq"
)
const (
host = "localhost"
port = 5432
user = "postgres"
password = "password"
dbname = "sampledb"
)
/*-------------------------------------------*\
|| Functions ||
\*-------------------------------------------*/
// Error Checking Fn
func CheckError(err error, str string) {
if err != nil {
fmt.Printf("Error # : %s\n", str)
panic(err)
}
}
/*-------------------------------------------*\
|| Main() ||
\*-------------------------------------------*/
func main() {
// Open DB Conn
psqlconn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable", host, port, user, password, dbname)
sql.Register("postgres", &pq.Driver{})
fmt.Printf(":: Drivers ::\n%s\n", sql.Drivers())
db, err := sqlx.Connect("postgres", psqlconn)
CheckError(err, "Main: sqlx.connect")
defer db.Close()
}
Error - w/ sql.Register
$ go run name-generator.go
panic: sql: Register called twice for driver postgres
goroutine 1 [running]:
database/sql.Register({0xa98bc9, 0x8}, {0xae6680, 0xc8a950})
C:/Program Files/Go/src/database/sql/sql.go:51 +0x13d
main.main()
C:/path/to/program.go:38 +0x11b
exit status 2
Additional Resources
Similar issue, but doesn't solve my problem Link
SQLX Documentation Link
SQL Documentation Link

Answer 1

The package github.com/lib/pq registers it's driver in an init function.
Remove the direct call to register the driver from the application:
sql.Register("postgres", &pq.Driver{}) <-- delete this line
Import github.com/lib/pq for the side effect of executing the init() function:
package main
import (
"fmt"
"database/sql"
"github.com/jmoiron/sqlx"
_ "github.com/lib/pq" // <-- add this line
)