Date in GoLang and MySQL Database

Install Libraries

Make sure Git is installed on your machine and in your system’s PATH. Install the package to your $GOPATH with the go tool from shell:

$ go get github.com/go-sql-driver/mysql

Create Database

Create a database with the name is learngodb. This database have 1 tables: Product table.

--
-- Table structure for table `invoice`
--

CREATE TABLE `invoice` (
  `id` int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
  `name` varchar(250) NOT NULL,
  `orderDate` date NOT NULL,
  `payment` varchar(250) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

--
-- Dumping data for table `invoice`
--

INSERT INTO `invoice` (`id`, `name`, `orderDate`, `payment`) VALUES
(1, 'Invoice 1', '2019-03-13', 'Paypal'),
(2, 'Invoice 2', '2019-03-21', 'Paypal'),
(3, 'Invoice 3', '2019-03-31', 'Cash'),
(4, 'Invoice 4', '2019-03-09', 'Cash');

Structure of Invoice Table

Data of Invoice Table

Create Entity

Create new folder named src. In src folder, create new folder named entities. In this folder, create new file named invoice_entity.go as below:

package entities

type Invoice struct {
	Id        int64
	Name      string
	OrderDate string
	Payment   string
}

Create Config

In src folder, create new folder named config. In this folder, create new file named config.go, this file is used to connect mysql database:

package config

import (
	"database/sql"
	_ "github.com/go-sql-driver/mysql"
)

func GetMySQLDB() (db *sql.DB, err error) {
	dbDriver := "mysql"
	dbUser := "root"
	dbPass := "123456"
	dbName := "learngodb"
	db, err = sql.Open(dbDriver, dbUser + ":" + dbPass + "@/" + dbName)
	return
}

Create Model

In src folder, create new folder named models. In models folder, create new file named invoice_model.go. This file contains methods to interact with the database.

package models

import (
	"database/sql"
	"entities"
	"time"
)

type InvoiceModel struct {
	Db *sql.DB
}

func (invoiceModel InvoiceModel) FindInvoicesBetween(from, to time.Time) ([]entities.Invoice, error) {
	rows, err := invoiceModel.Db.Query("select * from invoice where orderDate between ? and ?", from.Format("2006-01-02"), to.Format("2006-01-02"))
	if err != nil {
		return nil, err
	} else {
		invoices := []entities.Invoice{}
		for rows.Next() {
			var id int64
			var name string
			var orderDate string
			var status string
			err2 := rows.Scan(&id, &name, &orderDate, &status)
			if err2 != nil {
				return nil, err2
			} else {
				invoice := entities.Invoice{id, name, orderDate, status}
				invoices = append(invoices, invoice)
			}
		}
		return invoices, nil
	}
}

Structure of Project

Run Application

In src folder, create new file named main.go as below:

package main

import (
	"config"
	"fmt"
	"models"
	"time"
)

func main() {

	db, err := config.GetMySQLDB()
	if err != nil {
		fmt.Println(err)
	} else {
		invoiceModel := models.InvoiceModel{
			Db: db,
		}
		startDate, _ := time.Parse("2006-01-02", "2019-03-13")
		endDate, _ := time.Parse("2006-01-02", "2019-03-25")
		invoices, err2 := invoiceModel.FindInvoicesBetween(startDate, endDate)
		if err2 != nil {
			fmt.Println(err2)
		} else {
			for _, invoice := range invoices {
				fmt.Println("Id:", invoice.Id)
				fmt.Println("Name:", invoice.Name)
				fmt.Println("Order Date:", invoice.OrderDate)
				fmt.Println("Payment:", invoice.Payment)
				fmt.Println("----------------------------")
			}
		}
	}
}

Output

Id: 1
Name: Invoice 1
Order Date: 2019-03-13
Payment: Paypal
----------------------------
Id: 2
Name: Invoice 2
Order Date: 2019-03-21
Payment: Paypal
----------------------------