Using Clause
Introduction In PostgreSQL (and standard SQL in general), Clause is a structural component, a small block of code that forms a complete SQL statement (such as SELECT, INSERT, UPDATE, DELETE ). Each Clause begins with a designated keyword and handles a single task in the data processing lifecycle, helping you deal with everything from basic tasks like sorting and pagination to advanced techniques like recursive programming, asynchronous processing, or performance optimization. You can imagine an SQL statement like a train and the Clauses are the train cars hooked together in a strict logical order to transport and process data. Below are the important clauses supported by Postgres , divided by purpose of use: Selection & Duplicate Elimination Clauses DISTINCT is a clause located right within the SELECT statement used for Output Formatting/Filtering at the row level. It only operates at the final stage of the query process (after data has been filtered, aggregated and calcula...