Database CRUD Operations within Golang

This example separates CRUD operations into two sections which are ‘write’ and ‘read’. The ‘write’ section covers INSERT, UPDATE and DELETE queries. The ‘read’ section covers SELECT queries. We are also using context.WithTimeout to terminate long running queries. Pay attention to SELECT queries because they depend on something called MAX_EXECUTION_TIME.

INSERT/UPDATE/DELETE

Prepared (safe option)

Prefer this if you are not 100% sure that the query arguments are SQL Injection free.

It is a slow operation as it triples the number of network round-trips (Prepare, Execute and Close). The query uses ? argument placeholders.

Both examples below will work in exactly the same way so I suggest using the second one as it is cleaner. Also, whether the query arguments are dynamic or static, it still triples the number of network round-trips.

func Create(args ...interface{}) error {
	ctx, cancel := context.WithTimeout(context.Background(), 3 * time.Second)
	defer cancel()

	stmt, err := db.PrepareContext(ctx, `
INSERT INTO leagues
(uuid, name, address, int_rank, is_active, founded_at, created_at)
VALUES
(?, ?, ?, ?, ?, ?, UTC_TIMESTAMP())
`)
	if err != nil {
		return err
	}
	defer stmt.Close()

	res, err := stmt.ExecContext(ctx, args...)
	if err != nil {
		return err
	}

	tot, err := res.RowsAffected()
	if err != nil {
		return err
	}

	if tot != 1 {
		return errors.New("no rows were affected")
	}

	return nil
}

#go #mysql #golang

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Buddha Community

Spring Boot CRUD Operations

In the video in this article, we take a closer look at the Spring Boot CRUD Operations Example alongside Exception Handling!

In the video below, we take a closer look at the Spring Boot CRUD Operations example with exception handling. Let’s get started!

#spring boot #spring boot tutorial for beginners #crud #crud #crud #spring boot crud operations

Laravel 8 CRUD Operation Example

Hello Friend,

As you know Laravel 8 already officially released and today I will show you how to create CRUD operation in laravel 8, I have already perform many CRUD operations in my previous post like CRUD operation in ajax, CRUD operation in laravel 6 etc. So, today I will give you laravel 8 CRUD application example.

Laravel 8 CRUD Operation Example

https://websolutionstuff.com/post/laravel-8-crud-operation-example

#laravel #php #laravel 8 crud operation example #crud operation #laravel 8 crud tutorial #crud operation in laravel 8

System Databases in SQL Server

Introduction

In SSMS, we many of may noticed System Databases under the Database Folder. But how many of us knows its purpose?. In this article lets discuss about the System Databases in SQL Server.

System Database

Fig. 1 System Databases

There are five system databases, these databases are created while installing SQL Server.

• Master
• Model
• MSDB
• Tempdb
• Resource

Master

• This database contains all the System level Information in SQL Server. The Information in form of Meta data.
• Because of this master database, we are able to access the SQL Server (On premise SQL Server)

Model

• This database is used as a template for new databases.
• Whenever a new database is created, initially a copy of model database is what created as new database.

MSDB

• This database is where a service called SQL Server Agent stores its data.
• SQL server Agent is in charge of automation, which includes entities such as jobs, schedules, and alerts.

TempDB

• The Tempdb is where SQL Server stores temporary data such as work tables, sort space, row versioning information and etc.
• User can create their own version of temporary tables and those are stored in Tempdb.
• But this database is destroyed and recreated every time when we restart the instance of SQL Server.

Resource

• The resource database is a hidden, read only database that holds the definitions of all system objects.
• When we query system object in a database, they appear to reside in the sys schema of the local database, but in actually their definitions reside in the resource db.

#sql server #master system database #model system database #msdb system database #sql server system databases #ssms #system database #system databases in sql server #tempdb system database

Django-allauth: A simple Boilerplate to Setup Authentication

Django-Authentication 

A simple Boilerplate to Setup Authentication using Django-allauth, with a custom template for login and registration using django-crispy-forms.

Getting Started

Prerequisites

• Python 3.8.6 or higher

Project setup

# clone the repo
$ git clone https://github.com/yezz123/Django-Authentication

# move to the project folder
$ cd Django-Authentication

Creating virtual environment

• Create a virtual environment for this project:

# creating pipenv environment for python 3
$ virtualenv venv

# activating the pipenv environment
$ cd venv/bin #windows environment you activate from Scripts folder

# if you have multiple python 3 versions installed then
$ source ./activate

Configured Enviromment

Environment variables

SECRET_KEY = #random string
DEBUG = #True or False
ALLOWED_HOSTS = #localhost
DATABASE_NAME = #database name (You can just use the default if you want to use SQLite)
DATABASE_USER = #database user for postgres
DATABASE_PASSWORD = #database password for postgres
DATABASE_HOST = #database host for postgres
DATABASE_PORT = #database port for postgres
ACCOUNT_EMAIL_VERIFICATION = #mandatory or optional
EMAIL_BACKEND = #email backend
EMAIL_HOST = #email host
EMAIL_HOST_PASSWORD = #email host password
EMAIL_USE_TLS = # if your email use tls
EMAIL_PORT = #email port

change all the environment variables in the .env.sample and don't forget to rename it to .env.

Run the project

After Setup the environment, you can run the project using the Makefile provided in the project folder.

help:
 @echo "Targets:"
 @echo "    make install" #install requirements
 @echo "    make makemigrations" #prepare migrations
 @echo "    make migrations" #migrate database
 @echo "    make createsuperuser" #create superuser
 @echo "    make run_server" #run the server
 @echo "    make lint" #lint the code using black
 @echo "    make test" #run the tests using Pytest

Preconfigured Packages

Includes preconfigured packages to kick start Django-Authentication by just setting appropriate configuration.

Package	Usage
django-allauth	Integrated set of Django applications addressing authentication, registration, account management as well as 3rd party (social) account authentication.
django-crispy-forms	django-crispy-forms provides you with a crispy filter and {% crispy %} tag that will let you control the rendering behavior of your Django forms in a very elegant and DRY way.

Contributing

• Django-Authentication is a simple project, so you can contribute to it by just adding your code to the project to improve it.
• If you have any questions, please feel free to open an issue or create a pull request.

Download Details:
Author: yezz123
Source Code: https://github.com/yezz123/Django-Authentication
License: MIT License

#django #python 

Ternary operator in Python?

1. Ternary Operator in Python

What is a ternary operator: The ternary operator is a conditional expression that means this is a comparison operator and results come on a true or false condition and it is the shortest way to writing an if-else statement. It is a condition in a single line replacing the multiline if-else code.

syntax : condition ? value_if_true : value_if_false

condition: A boolean expression evaluates true or false

value_if_true: a value to be assigned if the expression is evaluated to true.

value_if_false: A value to be assigned if the expression is evaluated to false.

How to use ternary operator in python here are some examples of Python ternary operator if-else.

Brief description of examples we have to take two variables a and b. The value of a is 10 and b is 20. find the minimum number using a ternary operator with one line of code. ( **min = a if a < b else b ) **. if a less than b then print a otherwise print b and second examples are the same as first and the third example is check number is even or odd.

#python #python ternary operator #ternary operator #ternary operator in if-else #ternary operator in python #ternary operator with dict #ternary operator with lambda