Category: PostgreSQL Syntax

PostgreSQL CASE Expression The CASE expression in PostgreSQL is used to add conditional logic inside SQL queries.It works like if–else statements in programming languages. 1️⃣ CASE Expression Syntax Simple CASE CASE expression WHEN value1...

PostgreSQL ALL Operator The ALL operator in PostgreSQL is used to compare a value with every value returned by a subquery or array.The condition is TRUE only if it satisfies the comparison for all...

PostgreSQL ANY Operator The ANY operator in PostgreSQL is used to compare a value with any value returned by a subquery or array.The condition is TRUE if it matches at least one value. 🔹...

PostgreSQL EXISTS Operator The EXISTS operator in PostgreSQL is used to test whether a subquery returns any rows.It returns TRUE if the subquery returns at least one row, otherwise FALSE. 🔹 EXISTS checks for...

PostgreSQL HAVING Clause The HAVING clause in PostgreSQL is used to filter grouped results after the GROUP BY clause.While WHERE filters rows, HAVING filters groups. 1️⃣ Why HAVING? You cannot use aggregate functions (COUNT,...

PostgreSQL GROUP BY Clause The GROUP BY clause in PostgreSQL is used to group rows that have the same values in one or more columns and apply aggregate functions like COUNT, SUM, AVG, MAX,...

PostgreSQL JOINS JOINS in PostgreSQL are used to combine rows from two or more tables based on a related column (usually a primary–foreign key relationship). 1️⃣ Why Use JOINS? Example tables: users id name...

PostgreSQL SELECT Data The SELECT statement in PostgreSQL is used to retrieve data from tables. It is the most commonly used SQL command. 1️⃣ Basic SELECT

Select specific columns:

2️⃣ WHERE Clause...

PostgreSQL Operators Operators in PostgreSQL are symbols or keywords used to perform operations on data in SQL queries. They are mainly used in SELECT, WHERE, UPDATE, and DELETE statements. 1️⃣ Arithmetic Operators Used for...