18 Nov 2021 Show
Kateryna Koidan 5 SQL Subquery ExamplesSQL subqueries are basic tools if you want to communicate effectively with relational databases. In this article, I provide five subquery examples demonstrating how to use scalar, multirow, and correlated subqueries in the WHERE, FROM/JOIN, and SELECT clauses. A subquery, or nested query, is a query placed within another SQL query. When requesting information from a database, you may find it necessary to include a subquery into the SELECT, FROM , JOIN, or WHERE clause.16 Nov 2021 Kamila Ostrowska SQL for Startups – Do You Need It?If you’ve been wondering whether to use SQL in your startup, it’s probably high time to do so. SQL can be an amazing tool for small, fast-growing businesses. But don’t worry if you’re unfamiliar with SQL for startups. Maybe you are not sure what SQL is all about. Don’t worry; you don’t have to make any decisions this second! First, answer these questions: Can you think of any data related to your business – prices, clients, details about clients, production details, budget, costs, strategy, or anything else?18 Jun 2021 Martyna Sławińska An Overview of PostgreSQL Data TypesIt’s vital to know what you actually store in your database. That’s why every column has its data type. There are numerous PostgreSQL data types across various categories. Read on to see which data type suits which use case! In this article, we’ll go through the most common data types used in PostgreSQL. PostgreSQL, also called Postgres, is a well-known open-source object-relational database management system (DBMS). It is SQL-compliant, extensible, and includes all standard relational database features, such as database constraints, transactions, views, triggers, stored procedures, and more.17 Jun 2021 Kamila Ostrowska SQL Terms Beginners Should Know - Part 4Here it is – another batch of must-know SQL terms. In the first two parts, we covered tables, relational databases, queries, aliases, SQL JOINs, primary keys, and subqueries. Last time, we moved to more advanced terms like INSERT INTO, GROUP BY, and HAVING. Are you ready to dive deeper into SQL terminology? This is the fourth installment of our series on basic SQL terms for beginners (and everyone else). Don’t worry if you missed the previous articles; you can find Part 1 (essential SQL terms), Part 2, and Part 3 in our blog.7 Jul 2020 Agnieszka Kozubek-Krycuń What Is a SQL Dialect, and Which one Should You Learn?SQL, standard SQL, SQL Server, MySQL, PostgreSQL, Oracle, … You’d like to learn SQL, but you feel overwhelmed with keywords and you don’t know where to start. Let’s explain what each of those terms mean. SQL Is the Language for Talking to Databases A database is a computer program that can store and process large amounts of data. There are many different vendors of databases. PostgreSQL, MySQL, Oracle, and SQL Server are all database products by different vendors.3 Jan 2020 Rebecca McKeown SQL INSERT, SQL UPDATE, SQL DELETE – Oh My!Need to understand SQL INSERT, UPDATE, or DELETE? We'll get you up to speed with a comprehensive How-To and useful examples! SQL INSERT, UPDATE, and DELETE statements—what are they all about? If you're a data engineer, a database administrator, or even just your average data fanboy or girl, one day you're going to find yourself with a database that becomes your "baby." Charged with this special bundle of joy, you're going to need to feed and change the little fella.24 Dec 2019 Jakub Romanowski SQL, Databases, and Hollywood MoviesPolicemen, doctors, lawyers, scientists, teachers: These are the professions that we often see in Hollywood movies. But are movies also trying to show what the work of data analysts looks like? Here is a list of six movies in which screenwriters, directors, and producers decided to cast SQL and databases in the main roles. Data analysis is most often associated with business, reporting, and making key decisions for the company.8 Oct 2019 Ignacio L. Bisso SQL Order of OperationsSQL is not a traditional programming language in which you write a sequence of instructions in a given order of execution. Instead, SQL is a "declarative" language, which means that by writing a SQL query, you declare what data you expect as a result of the query, but you don't indicate how to obtain it. Six Operations to Order: SELECT, FROM, WHERE, GROUP BY, HAVING, and ORDER BY By using examples, we will explain the execution order of the six most common operations or pieces in an SQL query.25 Jan 2017 Jeffrey J. Keller Grouping, Rolling, and Cubing DataThe first two articles in this series highlighted SQL Server's ability to organize data into user-defined windows and its aggregate functions. Part 3 will focus on other methods of aggregating and organizing data using built-in SQL Server features – specifically, its grouping functions. For consistency, the same base data will be used as in the first two parts of this series. CREATE TABLE WindowTable (WindowID INT IDENTITY, House Varchar(32), FullName Varchar(64), PhysicalSkill Decimal(4, 2), MentalSkill Decimal (4, 2)) GOWhich function would enable you to eliminate those extra spaces you respond to eliminate extra spaces for consistency?The TRIM function is fundamental when we have text that has extra spaces in between words. What this function does is to remove these extra spaces and return words without the extra spaces at the beginning or end of text.
What function would you use to convert data in a SQL table from one datatype to another 1 point?In below example, the CONVERT() function is used to convert the decimal number 8.99 to another decimal number with zero scales. Example-3 : To convert a string to a datetime value : In below example, the CONVERT() function is used to convert the string '2020-05-14' to a datetime value.
What SQL function will return records with matching values in both tables?Note: The FULL OUTER JOIN keyword returns all matching records from both tables whether the other table matches or not.
Which SQL tool considers one or more conditions then returns a value as soon as a condition is met?A CASE statement considers one or more conditions and returns a value as soon as that condition is met.
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She asks Which sql function enables you to eliminate those extra spaces for consistency
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