Accessing an Oracle DB in Go

Aug 9, 2016 · 2 minute read · Comments

Oracle DB

Intro

This week I needed to access an Orable DB from GO and so I embarked on a journey that lasted almost 2 days. Everywhere I looked the documentation on how to get this going was not very intuitive so once I actually got it going, I decided to write my own how-to in order not to forget it.

How-To

Download Client files:
- instantclient-basic-macos.x64-12.1.0.2.0.zip
- instantclient-sdk-macos.x64-12.1.0.2.0.zip
- instantclient-sqlplus-macos.x64-12.1.0.2.0.zip
unzip in one directory say: /Oracle (this will create the /Oracle/instantclient_12_1 directory)

Create the oci8.pc file in the ‘/Oracle/instantclient_12_1’ directory and put this in it:

prefixdir=/Oracle/instantclient_12_1/sdk
libdir=${prefixdir}
includedir=${prefixdir}/include
    
Name: OCI
Description: Oracle database driver
Version: 11.2
Libs: -L${libdir} -lclntsh
Cflags: -I${includedir}

edit your .bashrc (or .zshrc) and put this in it:
- PKG_CONFIG_PATH=/Oracle/instantclient_12_1’
- LD_LIBRARY_PATH=/Oracle/instantclient_12_1’
Symlink the libraries to /usr/lib/
- ln -s /Oracle/instantclient_12_1/libclntsh.dylib.12.1 /usr/lib/libclntsh.dylib
- ln -s /Oracle/instantclient_12_1/libocci.dylib.12.1 /usr/lib/libocci.dylib
- NOTE: if you are using a Mac and you are on El Capitan, you will need to disable ‘rootless’ protection
  - Reboot in recovery mode (Press Cmd-R during the reboot)
  - Start a command line and run the command: ‘csrutil disable’
  - Reboot again
  - Now you can enter the symlinks as above.
run: ‘go get github.com/mattn/go-oci8’
All Set

edit oracle_db.go:

package main
    
import (
    "fmt"
    "database/sql"
    _ "github.com/mattn/go-oci8"
)
    
func main(){
    db, err := sql.Open("oci8", "username/password@localhost:1521/xe")
    if err != nil {
        fmt.Println(err)
        return
    }
    defer db.Close()
    
    if err = db.Ping(); err != nil {
        fmt.Printf("Error connecting to the database: %s\n", err)
        return
    }
    
    rows,err := db.Query("select 2+2 from dual")
    if err != nil {
        fmt.Println("Error fetching addition")
        fmt.Println(err)
        return
    }
    defer rows.Close()
    
    for rows.Next() {
        var sum int
        rows.Scan(&sum)
        printf("2 + 2 always equals: %d\n", sum)
    }
}

go run oracle_db.go
- should see printed on the console: ‘2+2 always equals: 4’

In The End

I hope this helps someone else to come to terms with accessing an oracle DB from golang.

Happy GOing!!

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Paul Fortin

Accessing an Oracle DB in Go

Intro

How-To

In The End