PostgreSQL – 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 […]
Category Archives: postgresql
PostgreSQL – CONSTRAINTS Constraints are the rules enforced on data columns on table. These are used to prevent invalid data from being entered into the database. This ensures the accuracy and reliability of the data in the database. Constraints could be column level or table level. Column level constraints are applied only to one column […]
PostgreSQL – SELECT Query PostgreSQL SELECT statement is used to fetch the data from a database table, which returns data in the form of result table. These result tables are called result-sets. Syntax The basic syntax of SELECT statement is as follows − SELECT column1, column2, columnN FROM table_name; Here, column1, column2…are the fields of […]