SQL’s Role in Application Development

SQL’s Role in Application Development
You’ve know about using SQL with databases. How does SQL fit in with app development? In this post, we look at the app development process, how it intersects with modeling a database, and what developers can do with SQL outside of their app. Obviously, the beginning of this process is defining your app — what it does, who it is for, how it will function and look, etc. Let’s say you’ve done that work already and you’re preparing to start the more detailed stuff.

The Complete Beginner’s Guide to SQL Fundamentals

Vertabelo Academy is a great place to learn SQL. If you’re a complete beginner, it’s best to have an overview of what SQL is, what a database is, and how they work together. In this article, you’ll find a quick explanation of all you need to get started with SQL. The Database You might have already heard that SQL is used with databases. What exactly is a database? In the most general sense, it is an organized collection of various kinds of data.

Finding the Perfect SQL Job

So you have some SQL skills and you’re looking for a job that will use them. What are your options? SQL is everywhere, and there’s a huge demand for people with database management skills. This is especially the case when companies start implementing Big Data solutions and strategies. There’s no arguing that SQL is a must-have skill. If you’re already proficient, how can you put your expertise to practical use in the job market?

A Day in the Life of an SQL Developer

Describing a “typical” day for an SQL developer is not easy. When your daily work is using various technologies to create interesting database-oriented products, very few days are alike! Each day brings a new and intriguing challenge. Nevertheless, I’ll have a go at explaining what everyday things an SQL developer might do. Morning: Arrive at Work The cornerstone of any software engineering endeavor is caffeine, and lots of it.

Performing Calculations on Date- and Time-Related Values

Relational databases support several date and time data types. In this article, we’ll look at several arithmetic operations we can do on these types. These operations are logical and understandable, even for the beginning SQL coder. Let’s first briefly explain the main data types used for dates and times. Keep in mind that data types may differ by database engine, so check your database documentation for specifics before you start working with them.

Getting the Hang of the GROUP BY Clause

GROUP BY is an important part of the SQL SELECT statement. But new SQL coders can run into some problems when this clause is used incorrectly. Here’s how to avoid those issues. You’re learning SQL. You know how to SELECT some data FROM a table and how to filter the data with a WHERE clause. You can process the data using aggregate functions (MIN, MAX, SUM, AVG, and others). But when you’re dealing with a lot of data, you may need to narrow it down even more.

SQL and Your Next Job

The tech sector is experiencing strong job growth. Should SQL be on your list of must-have skills? If you’re even remotely interested in finding a new job, you’ve probably noticed that IT jobs are hot. Not only are a lot of these jobs available, they offer some pretty great opportunities to challenge yourself, grow, and build new skills. And the compensation tends to be pretty awesome too. In today’s world, technology is evolving at an almost daily pace, and this is producing a flood of data that has to be managed.

Text Data Types in SQL

How can you store textual information in database tables? Read this post to discover your options. Note: This post is intended for readers familiar with SQL data definition language (DDL) and the DDL CREATE statement. To learn more about DDL, check out Vertabelo SQL Academy. Most data types are classified as NUMERIC, CHARACTER, or DATE. In this post, we’re going to focus on TEXTUAL or CHARACTER data types. These data types handle groups of alphanumeric characters – i.

Refine Results with SQL Set Operators

Using UNION, UNION ALL, EXCEPT, and INTERSECT to manage SQL query results. The function of SQL set operators is pretty simple; they allow us to combine results from different SQL queries into one result set. The best way to understand how set operators work is to use visual methods like the Venn diagram. For those of you not familiar with Venn diagrams, they are two circles that represent items or collections of items.

6 Common Syntax Mistakes All SQL Learners Make

We all make mistakes when learning a new language – especially at the beginning. New words, complicated grammar… Everyone needs time to master a language. But when we get immediate feedback, we can progress more quickly. The same goes for learning SQL. Mastering SQL Queries Interactive SQL courses are one way to get immediate feedback on your queries. These courses, like the ones offered in Vertabelo Academy, usually introduce new concepts and then ask you to have a go at them right away.

8 Tips Absolute Beginners Can Use to Fix SQL Queries

Code errors are common – and frustrating. And when you’re just learning SQL, it can be very challenging to find and fix your mistakes. In this post, we’ll show you eight ways to solve or eliminate common SQL coding errors. Today, we’ll talk about some tips the SQL beginner can use to avoid several common errors. These tips work in any database environment. As we go along, we’ll be showing some error messages.

6 Ways You Can Learn SQL

Learning a new skill can be a daunting task, especially in programming. SQL is not immune to this. Luckily, with the Internet and the explosion of programming-related information out there, we have a lot of options! But we then come to a new roadblock. Where to begin? How will we know which option is best for our budget, skill level, and schedule? This article tackles these questions and gives you a roadmap – or should we say a couple of them – of your journey towards SQL proficiency.

Correlated SQL Subqueries For Newbies

Correlated subqueries are the only way to solve some SQL statements. But they can be very slow. In this post, we’ll talk about why, how, and when to use them. Subqueries are an important resource for increasing the expressive power of SQL. If you haven’t read our previous article, subqueries are simply a SELECT statement inside another SELECT. We can use them in different places inside a SELECT, such as in the WHERE, HAVING, or FROM clauses.

SQL Errors: Five Common SQL Mistakes

As you learn SQL, watch out for these common coding mistakes You’ve written some SQL code and you’re ready to query your database. You input the code and …. no data is returned. Instead, you get an error message. Don’t despair! Coding errors are common in any programming language, and SQL is no exception. In this post, we’ll discuss five common mistakes people make when writing SQL. Watch Your Language (and Syntax) The most common SQL error is a syntax error.

SQL Errors: Five Common SQL Mistakes

As you learn SQL, watch out for these common coding mistakes You’ve written some SQL code and you’re ready to query your database. You input the code and …. no data is returned. Instead, you get an error message. Don’t despair! Coding errors are common in any programming language, and SQL is no exception. In this post, we’ll discuss five common mistakes people make when writing SQL. Watch Your Language (and Syntax) The most common SQL error is a syntax error.

GROUP BY Clause: How Well Do You Know It?

The database can do different kinds of computations: it can add and subtract, multiply and divide, it can do computations on dates, it can count rows and sum row values, and so on. It can also do quite sophisticated statistics. The GROUP BY clause is the most basic way to compute statistics in SQL. It can be quite tough for beginners but it is really powerful. Let’s look at the details of the GROUP BY clause, starting with the basics.

Do It in SQL: Recursive Tree Traversal

In the previous article, I described how to use Common Table Expressions to find the shortest path in a directed graph. That example could be hard to follow, I admit. Let’s do something much more common, something that is implemented on almost every website – a menu. But… we’ll do as much as possible in a single SQL query instead of writing the code. We’ll use CTEs for PostgreSQL and the hierarchical query clause for Oracle.

SQL joins

A SQL JOIN is a method to retrieve data from two or more database tables. This article presents a basic overview of what data from a particular SQL join will look like. A popular way of understanding SQL joins is to visualize them using Venn diagrams, so each example have corresponding Venn diagram, appropriate SELECT statement and the result table. There are a few major kinds of SQL joins:

SQL Subqueries

The article describes what a subquery is and what these useful statements look like. We will cover basic examples with the IN, EXISTS, ANY, and ALL operators, look at subqueries in from and where clauses, and explore the difference between correlated and nested subqueries. First, let’s start with an example database. To present some of these statements we need to have an example table and fill it with some data.

How to Tackle SQL NULLs: The NULLIF Function

Usually we try to avoid NULLs, but sometimes we need to have a NULL instead of an actual value. When this need pops up, a helpful but little-known SQL function called NULLIF makes it possible. This post will introduce you to NULLIF and demonstrate its use in two example cases. In the article How to Tackle NULLS: The COALESCE Function , we got to know the COALESCE function. It returns the first not-null expression.

SQL JOIN Made Easy

You’re probably already familiar with simple SQL queries, such as “SELECT * FROM table”. Now you are wondering what to do when you have multiple tables and you want to join them. Exactly! JOIN is the key. In this tutorial, you will learn how to connect data from multiple tables using SQL JOINs. What are SQL JOINs? Databases usually have more than one table. JOINs are an SQL construction used to join data from two or more tables.

How to Tackle SQL NULLs: COALESCE function

It’s inevitable that some data in the database has no value what in SQL is represented by the NULL keyword. “No value” here is different from zero, false, or an empty string (but with exceptions! In Oracle database, NULL is the same as string of zero length). During playing with the database, treating NULLs are becoming more and more troublesome, therefore >MySQL standard provides help with some of the functions, like COALESCE.

Why Should I Learn SQL?

There are 250+ computer programming languages in popular use. Why should you learn SQL, or Structured Query Language? Why Should I Learn SQL? Are you interested in boosting your career? Wondering what skills are worth investing in? If you’re currently in your dream job, still searching for it, or even thinking about starting your own business, it pays to develop your technical skills. A solid technical background is highly in demand among recruiters, and it provides the necessary underpinnings for managing the IT side of your business.

Get to Know the Power of SQL Recursive Queries

Level: Advanced Most commonly, the SQL queries we run on a database are quite simple. Well, that depends on your role, of course. Analysts in data warehouses retrieve completely different sorts of information using (very often) much more complicated queries than software engineers creating CRUD applications. However, sometimes it’s simpler or more elegant to run a query that is a little bit more sophisticated without needing further data processing in the code.