panic: runtime error: invalid memory address or nil pointer dereference panic: runtime error: invalid memory address or nil pointer dereference

[Eva Yuen]

I'm trying to get data out of postgres with golang. I keep getting this pointer error. With reflect I have checked the database has been connected properly. Could anybody offer any advice on how to deal with this error 

panic: runtime error: invalid memory address or nil pointer dereference panic: runtime error: invalid memory address or nil pointer dereference

[signal 0xb code=0x1 addr=0x20 pc=0x4a0041]

goroutine 1 [running]:

database/sql.(*Rows).Close(0x0, 0x0, 0x0)

/home/syuan/.gvm/gos/go1.4/src/database/sql/sql.go:1659 +0x31

database/sql.(*Rows).Next(0x0, 0x1)

/home/syuan/.gvm/gos/go1.4/src/database/sql/sql.go:1586 +0x25

main.getpsql()

/home/syuan/src-git/blue-prometheus/examples/postgres/main.go:40 +0x41e

main.main()

/home/syuan/src-git/blue-prometheus/examples/postgres/main.go:59 +0x1b

goroutine 5 [chan receive]:

database/sql.(*DB).connectionOpener(0xc208036000)

/home/syuan/.gvm/gos/go1.4/src/database/sql/sql.go:589 +0x4c

created by database/sql.Open

/home/syuan/.gvm/gos/go1.4/src/database/sql/sql.go:452 +0x31c

goroutine 17 [syscall, locked to thread]:

runtime.goexit()

/home/syuan/.gvm/gos/go1.4/src/runtime/asm_amd64.s:2232 +0x1

exit status 2

code is here :

package main

import (

        "log"

        "fmt"

        "reflect"

        _ "github.com/lib/pq"

        "database/sql"

)

func getpsql() {

        fmt.Println(sql.Drivers())

        db, err := sql.Open("postgres","user=blue dbname=blue password=blue sslmode=disable")

        if err !=nil {

                log.Fatal(err)

        }

        err = db.Ping()

        if err != nil {

                panic(err.Error())

        }

        rows, err :=db.Query("select * from napkin_stats limit 3")

        fmt.Println(reflect.TypeOf(rows))

        defer rows.Close()

        for rows.Next() {

                var counter int

        if err = rows.Scan(&counter);err != nil {

                panic(err)

        }

        }

}

func main() {

        getpsql()

}

[andrey mirtchovski]

> rows, err :=db.Query("select * from napkin_stats limit 3")
> fmt.Println(reflect.TypeOf(rows))
> defer rows.Close()

the panic message tells you that rows is nil, therefore I suspect that
db.Query returns an error which you're not checking.

[Eva Yuen]

thanks solved

[kak...@gmail.com]

in my code problem solved by adding sslmode=disable in sql.Open ...

[Tyler Compton]

I think you should file an issue about that.