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
+13.3k Golang : Parsing or breaking down URL
+3.9k PHP : Extract part of a string starting from the middle
+3.6k Adding Skype actions such as call and chat into web page examples
+16.7k Golang : Convert IPv4 address to decimal number(base 10) or integer
+8.4k Facebook : Getting the friends list with PHP return JSON format
+10k How to test Facebook App on localhost ?
+10.7k Golang : Calculations using complex numbers example
+5.6k Golang : How to determine if request or crawl is from Google robots
+22.8k Golang : Find biggest/largest number in array
+11.6k Golang : Transform comma separated string to slice example
+15.1k Golang : Check if a string contains multiple sub-strings in []string?
+17.6k Golang : Populate dropdown with html/template example