Author: admin
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Key Features of REST APIs
REST APIs are built around six fundamental principles, some of which we have already touched on. Let’s take a closer look at each of the six principles below.
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Why Use a REST API?
Many different types of APIs are available; however, RESTful APIs have become the go-to technology for almost every API in production today. This is not by chance but due to the simplicity and scalability of implementing and supporting REST technologies. The sheer amount of frameworks and technologies available to develop and support REST APIs alone…
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What is a REST API?
A REST (Representational State Transfer) API is a mechanism that allows different software applications to communicate with each other over the internet or local network. REST APIs follow specific rules and standards that enable applications and users to use HTTP requests to access and use data. The data sent and received by a REST API…
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Introduction
When building APIs, a RESTful API is one of the most common types of API to build. As with any technology, REST APIs can be built to serve straightforward use cases or be augmented to accommodate your most complex tasks. Regardless of what you are building, you’ve come here to figure out how to build…
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DISTINCT Keyword
The PostgreSQL DISTINCT keyword is used in conjunction with SELECT statement to eliminate all the duplicate records and fetching only unique records. There may be a situation when you have multiple duplicate records in a table. While fetching such records, it makes more sense to fetch only unique records instead of fetching duplicate records. Syntax Example First,…
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HAVING Clause
The HAVING clause allows us to pick out particular rows where the function’s result meets some condition. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause. Syntax The following is the position of the HAVING clause in a SELECT query −…
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WITH Clause
In PostgreSQL, the WITH query provides a way to write auxiliary statements for use in a larger query. It helps in breaking down complicated and large queries into simpler forms, which are easily readable. These statements often referred to as Common Table Expressions or CTEs, can be thought of as defining temporary tables that exist…
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GROUP BY
The PostgreSQL GROUP BY clause is used in collaboration with the SELECT statement to group together those rows in a table that have identical data. This is done to eliminate redundancy in the output and/or compute aggregates that apply to these groups. The GROUP BY clause follows the WHERE clause in a SELECT statement and precedes the…
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ORDER BY Clause
The PostgreSQL ORDER BY clause is used to sort the data in ascending or descending order, based on one or more columns. Syntax The basic syntax of ORDER BY clause is as follows −SELECT column-list FROM table_name [WHERE condition] [ORDER BY column1, column2, .. columnN] [ASC | DESC]; You can use more than one column in the…
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LIMIT Clause
The PostgreSQL LIMIT clause is used to limit the data amount returned by the SELECT statement. Syntax The basic syntax of SELECT statement with LIMIT clause is as follows − The following is the syntax of LIMIT clause when it is used along with OFFSET clause − LIMIT and OFFSET allow you to retrieve just a portion…