# Connecting with Go
This guide explains how to establish a connection between a **Go (Golang)** application and a **PostgreSQL** database using the `github.com/lib/pq` driver. It walks through the necessary setup, configuration, and execution of a simple SQL query.
### **Variables**
To connect to a PostgreSQL database, you only need one environment variable — the **connection URI**. This URI contains all the necessary information like username, password, host, port, and database name.
Variable
Description
Purpose
**POSTGRESQL\_URI**
Full PostgreSQL connection string (from the Elestio service overview page)
Provides all necessary credentials and endpoint details in a single URI format.
The URI will look like this:
```bash
postgresql://:@:/
```
You can find the details needed in the URI from the **Elestio service overview** details. Copy and replace the variables carefully in the URI example provided above.
### **Prerequisites**
##### **Install Go**
Check if Go is installed by running:
```bash
go version
```
If not installed, download and install it from [https://go.dev/dl/](https://go.dev/dl/).
##### **Install `pq` Package**
Install the `pq` driver using:
```bash
go get github.com/lib/pq
```
### **Code**
Once all prerequisites are set up, create a new file named `main.go` and add the following code, and replace the `POSTGRESQL_URI` with actual link or in environment setup as you wish:
```go
package main
import (
"database/sql"
"fmt"
"log"
"net/url"
_ "github.com/lib/pq"
)
func getDBConnection(connectionString string) (*sql.DB, error) {
parsedURL, err := url.Parse(connectionString)
if err != nil {
return nil, fmt.Errorf("Failed to parse connection string: %v", err)
}
db, err := sql.Open("postgres", parsedURL.String())
if err != nil {
return nil, fmt.Errorf("Failed to open database connection: %v", err)
}
return db, nil
}
func main() {
connectionString := "POSTGRESQL_URI"
db, err := getDBConnection(connectionString)
if err != nil {
log.Fatal(err)
}
defer db.Close()
query := "SELECT current_database(), current_user, version()"
rows, err := db.Query(query)
if err != nil {
log.Fatal("Failed to execute query:", err)
}
defer rows.Close()
for rows.Next() {
var dbName, user, version string
if err := rows.Scan(&dbName, &user, &version); err != nil {
log.Fatal("Failed to scan row:", err)
}
fmt.Printf("Database: %s\nUser: %s\nVersion: %s\n", dbName, user, version)
}
}
```
To execute the script, open the terminal or command prompt and navigate to the directory where `main.go`. Once in the correct directory, run the script with the command
```bash
go run main.go
```
If the connection is successful, the terminal will display output similar to:
```
Database: Elestio
User: postgres
Version: PostgreSQL 16.8 (Debian 16.8-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
```