Golang : GORM read from database example
Just a simple tutorial on how to use GORM(Golang Object Relational Map) to connect to a MySQL/MariaDB database and read data from it.
Here you go!
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jinzhu/gorm"
"time"
)
// Activities table SQL :
// id bigint(20) AUTO_INCREMENT
// username varchar(50)
// created_on timestamp
// action char(1)
// description varchar(300)
// visibility char(1)
type Activities struct {
Id int `sql:"AUTO_INCREMENT"`
Username string `sql:"varchar(50);unique"`
Created_On time.Time
Action string `sql:"type:char(1)"`
Description string `sql:"type:varchar(300)"`
Visibility string `sql:"type:char(1)"`
}
func main() {
dbConn, err := gorm.Open("mysql", "username:password@tcp(xx.xxx.xxx.xxx:3306)/database_name?charset=utf8&parseTime=true")
if err != nil {
fmt.Println(err)
}
// init
dbConn.DB()
dbConn.DB().Ping()
dbConn.DB().SetMaxIdleConns(10)
dbConn.DB().SetMaxOpenConns(100)
activity := Activities{} // a record
// get first record
dbConn.First(&activity)
fmt.Println(activity)
fmt.Println("------------------------------")
// get all records
activities := []Activities{} // a slice
//dbConn.Find(&activities)
//fmt.Println(activities)
// get records from record offset 1 to 10
// useful for pagination purpose! - just need to calculate the offset and limit dynamically
dbConn.Limit(10).Order("id asc").Find(&activities).Offset(1).Order("id asc").Find(&activities)
for _, v := range activities {
fmt.Println("Id : ", v.Id)
fmt.Println("Username : ", v.Username)
fmt.Println("Created On : ", v.Created_On)
fmt.Println("Action : ", v.Action)
fmt.Println("Desription : ", v.Description)
fmt.Println("Visibility : ", v.Visibility)
}
}
NOTE : Without the &parseTime=true
parameter in the dbConn configuration. Your driver will have problem reading(scanning) and translating the SQL timestamp.
References :
https://en.wikipedia.org/wiki/Object-relational_mapping
https://www.socketloop.com/tutorials/golang-connect-to-database-mysql-mariadb-server
See also : Golang : Connect to database (MySQL/MariaDB) server
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+3.9k Javascript : How to get width and height of a div?
+16.1k Golang : How to make a file read only and set it to writable again?
+11.1k Golang : convert(cast) string to integer value
+9k CodeIgniter : Load different view for mobile devices
+9.4k Golang : ISO8601 Duration Parser example
+7.9k Golang : How to get username from email address
+17.6k Golang : Get host name or domain name from IP address
+12.6k Golang : How to determine if a year is leap year?
+16.1k Golang : Qt image viewer example
+5k Linux/MacOSX : Search for files by filename and extension with find command
+10k Golang : Fix fmt.Scanf() on Windows will scan input twice problem
+6.5k Golang : Convert(cast) io.Reader type to string