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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 […]

PostgreSQL – 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 […]

PostgreSQL – 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 […]