https://github.com/mpolinowski/go-postgres
Using the `pq` package to connect a Go application to Postgres14
https://github.com/mpolinowski/go-postgres
golang pg postgres
Last synced: about 2 months ago
JSON representation
Using the `pq` package to connect a Go application to Postgres14
- Host: GitHub
- URL: https://github.com/mpolinowski/go-postgres
- Owner: mpolinowski
- Created: 2021-10-16T10:55:31.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2021-10-16T10:55:34.000Z (over 4 years ago)
- Last Synced: 2025-01-28T19:17:25.974Z (over 1 year ago)
- Topics: golang, pg, postgres
- Language: Go
- Homepage:
- Size: 129 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Postgres with Go
- [PostgreSQL v14 Setup](#postgresql-v14-setup)
- [Create a Database and Tables](#create-a-database-and-tables)
- [Setting up pgadmin (optional)](#setting-up-pgadmin-optional)
- [Let's Go](#lets-go)
- [Operations](#operations)
- [Adding New Data](#adding-new-data)
- [Updating Data](#updating-data)
- [Deleting Data](#deleting-data)
- [Reading Data](#reading-data)
## PostgreSQL v14 Setup
```bash
docker run -d --rm \
--name postgres \
-e POSTGRES_PASSWORD=secretpassword \
-p 5432:5432 \
postgres:14
```
```bash
docker exec -ti -u postgres postgres psql
psql (14.0 (Debian 14.0-1.pgdg110+1))
Type "help" for help.
postgres=#
```
## Create a Database and Tables
```sql
CREATE DATABASE gocam;
```
```sql
\c gocam;
You are now connected to database "gocam" as user "postgres".
```
```sql
CREATE TABLE alarm_rec (camera_id INT, rec_path VARCHAR(100), created_at TIMESTAMP NOT NULL DEFAULT NOW());
```
## Setting up pgadmin (optional)
> Make sure that your database is accessible via the external IP address of your server, e.g. `ufw allow 5432/tcp` !
```bash
docker pull dpage/pgadmin4:latest
```
```bash
docker run -p 8080:80 \
--name pgadmin \
-e 'PGADMIN_DEFAULT_EMAIL=user@domain.com' \
-e 'PGADMIN_DEFAULT_PASSWORD=secretpassword' \
-d dpage/pgadmin4:latest
```
Login with the default email and password and open the dashboard on port `8080`. Select to add your Postgres Server:
## Let's Go
```bash
go mod init github.com/mpolinowski/go-postgres
go get github.com/lib/pq
```
```go
package main
import (
"database/sql"
"fmt"
"time"
_ "github.com/lib/pq"
)
const (
host = "192.168.2.111"
port = 5432
user = "postgres"
password = "secretpassword"
database = "gocam"
)
func main() {
// Build the database connection string
psqlconn := fmt.Sprintf("host=%s port=%d user=%s password=%s database=%s sslmode=disable", host, port, user, password, database)
// Connect to database using the sql package
db, err := sql.Open("postgres", psqlconn)
CheckError(err)
// Make sure connection is closed when done
defer db.Close()
// Verify you are connected and log result
err = db.Ping()
CheckError(err)
fmt.Println(time.Now().Format(time.RFC850), ":: Connected to database")
}
func CheckError(err error) {
if err != nil {
panic(err)
}
}
```
Test run with `go run ./src/sql/main.go`:
```bash
go run ./src/sql/main.go
Saturday, 16-Oct-21 17:36:36 CST :: Connected to database
```
### Operations
#### Adding New Data
Adding data to our `alarm_rec` table:
```go
// Insert static data
insertData := `INSERT INTO "alarm_rec"("camera_id", "rec_path") VALUES('0001', '/opt/rec/12332423dsfsd232.snap')`
_, e := db.Exec(insertData)
CheckError(e)
// Insert dynamic data
camID := 0002
recPath := "/opt/rec/546sdgv2314sdfgd232.snap"
insertVarData := `INSERT INTO "alarm_rec"("camera_id", "rec_path") VALUES($1, $2)`
_, e = db.Exec(insertVarData, camID, recPath)
CheckError(e)
```
#### Updating Data
```go
// Update a row
updateData := `UPDATE "alarm_rec" SET "rec_path"=$1 WHERE "camera_id"=$2`
_, e := db.Exec(updateData, "/opt/rec/false_positive/546sdgv2314sdfgd232.snap", 0001)
CheckError(e)
```
#### Deleting Data
```go
// Delete a row
deleteData := `DELETE FROM "alarm_rec" WHERE "camera_id"=$1`
_, e := db.Exec(deleteData, 0001)
CheckError(e)
```
#### Reading Data
```go
selectData := `SELECT "rec_path" FROM "alarm_rec" WHERE "camera_id"=$1`
rows, err := db.Query(selectData, 0002)
CheckError(err)
defer rows.Close()
for rows.Next() {
var path string
err = rows.Scan(&path)
CheckError(err)
fmt.Println(path)
}
CheckError(err)
```
```bash
go run ./src/sql/main.go
Saturday, 16-Oct-21 18:50:33 CST :: Connected to database
/opt/rec/546sdgv2314sdfgd232.snap
```