Databases 11 results

Relational Algebra and TeamSQL – Part II

Sometimes is good to dive into the foundations of something, to find new elements to add more power to our current skills. This article is the second part of the previous week Relational Algebra article. In Relational Algebra, there are several data operations, and almost all of them have a simple SQL statement representing the same process. However, there is one Algebra Relational operator that is not simple to express in SQL: The division operator. In this article, we will cover the division ...

Relational Algebra and TeamSQL

In this article about Algebra Relational, we will cover a very rare in SQL operation called division. This operator has not an equivalent implementation in SQL. However, there is a technique to implement division in SQL, and we will explain here.   Relational Algebra: Division, what is it? As any other algebra, relational algebra has operations (like addition subtraction multiplication division in numeric algebra). The fundamental operations are Selection and Projection. We will base ...

Avoiding Duplication Of Records

The issue of avoiding duplicate records in relational databases is one of the most common issues or problems. The primary mechanism to prevent that are the primary keys, however, in many databases or tables, primary keys are not defined. We are not going to discuss if not having a primary key is unacceptable or acceptable under the specific circumstance. We know that occurs, especially on data warehouses schemas. Then, in this environment where we don’t have primary keys or unique constraints ...

A Day At Races With TeamSQL 🏎

A DAY AT THE RACES WITH TEAMSQL In this article, we took a public database with real and historical data about formula one races located at http://ergast.com/mrd/db/, we imported into a PostgreSQL database engine, and then we start querying using TeamSQL trying to cover and use a broad spectrum type of business queries and at the same time using different SQL clauses. We expect you can find some of the exciting queries presented here usable and applicable perhaps to your business data. ...

Slow Query Improvement

HOW A GOOD INDEX STRATEGY CAN HELP POLICE SUCCESS As SQL developers, we are usually focused on creating queries which return the correct results. This is a good principle. However, there are more things to take into consideration when you create a query. One of them is the query performance. You think that query response time is not essential.? In this article, we will cover one example where query response time is critical.   SCENE ONE: 911 CALL CENTER Let’s suppose we are at the ...

What Is JSON?

JSON is a data interchange format that is designed to be lightweight and easy to work with. It’s quite popular in web applications, and it can be considerably more flexible than a traditional relational data model. Several database engines support JSON, so you can store JSON data and use functions to operate on it. This includes decomposing, transforming, or even creating JSON data from regular relational data.   What Is JSON? JSON is an acronym for JavaScript Object Notation. It ...

Getting Started with Charts in TeamSQL

Prerequisites Before you begin, please be sure to: Download and install TeamSQL Sign up for a TeamSQL account and use your credentials to log into your local instance of TeamSQL Connect to a database that contains the data you want to chart.   Creating a Chart The first thing you’ll need to do is open up a new query window.   Write your query and execute it so that you return the data you want to chart.       Notice that ...

Adding a new database connection

In the Explorer pane, click on the plus icon next to CONNECTIONS.   This launches the Add Connection window where you can create new connections from TeamSQL to your server(s).   To create a connection to a MySQL database set the Database Type to MySQL.   Note how the window now displays Create a new MySQL connection at the top. To connect to your MySQL database server, you’ll need to provide the following parameters to TeamSQL:   &...

Which database engines will you support?

In addition to MySQL, Microsoft SQL Server, PostgreSQL and AWS Redshift, we will be supporting those engines in the following weeks: Oracle MariaDB Elastic (ElasticSearch) mongoDB redis Cassandra AWS Aurora SQLite    

Connection Microsoft SQL Server over TCP/IP

You must enable TCP/IP connection of Microsoft SQL Server, so you can connect it to from TeamSQL. It's required. Please check this out to enable TCP/IP Connection of Microsoft SQL Server : https://technet.microsoft.com/en-us/library/hh231672(v=sql.110).aspx Checks these first: Start the "SQL SERVER BROWSER" Service in Windows services if it's not already started. See: https://technet.microsoft.com/en-us/library/ms165734(v=sql.90).aspx Host name cannot be "." (dot) SQL Server ...

Saving and Managing Queries in TeamSQL

You can easily save the queries you execute in TeamSQL for future reference.     You can initiate a save by clicking Save Query, using CTRL + S (in Linux or Windows), or using ⌘ + S (in macOS). You will be prompted to provide a name for your query if this is the first time you’ve saved.   TeamSQL now displays the name of your query in the query’s tab, as well as in the left-hand navigation bar.   Viewing Your Saved Queries In addition to accessing ...