Postgres and Open Source Experts

24x7x365 since 1997

Education

Professional Postgres and Open Source support

Command Prompt, Inc., is the oldest Postgres Company in North America and one of the oldest Open Source firms still operating today. We serve our clients with best in class expertise and professionalism. You can read more about support and services here:


You have landed at the largest single source of Postgres education blogs in the world. At Command Prompt, we believe deeply that the education of the community is critical to the continued success of Postgres and related technologies. We hope you find content you are looking for and don't hesitate to Contact us today for all your Postgres and Open Source consulting and support needs.

How to Use HAVING Clause in PostgreSQL

In Postgres, the HAVING clause is mostly used with the GROUP BY clause to filter the group/aggregate based on some specific condition.

How to Use DISTINCT Keyword in PostgreSQL

In PostgreSQL, the DISTINCT keyword/clause is used within the SELECT statement to fetch the unique records from the result-set.

How to Use ORDER BY Clause in PostgreSQL

In PostgreSQL, specify the ORDER BY clause and column name followed by the ASC or DESC to sort the result set in ascending or descending order, respectively.

How to Use DELETE Query in PostgreSQL

In PostgreSQL, the DELETE query can be used with or without the WHERE clause to delete a single, multiple, or all the rows of a specific table.

How to Use Update Query in PostgreSQL

In PostgreSQL, the UPDATE query is used with the assistance of the SET clause to update or modify the table’s record/data.

How to Use Select Query in PostgreSQL

The SELECT statement is used to fetch one or more columns of a table. It returns a resultant table which is known as the result set or result table.

How to Use AND & OR Operators in PostgreSQL

In PostgreSQL, the AND and OR operators are used to combine more than one condition and are referred to as conjunctive, logical, or boolean operators.

How to Use WHERE Clause in PostgreSQL

In PostgreSQL, the WHERE clause is used to filter the results of different statements such as SELECT, DELETE, UPDATE, etc.

How to Rename the columns of a table in PostgreSQL

PostgreSQL provides a RENAME COLUMN clause that is used with the collaboration of ALTER TABLE command to rename a column.

How to Change/Modify Column Type in PostgreSQL

In PostgreSQL, the “ALTER TABLE” and “ALTER COLUMN” commands, along with the TYPE Keyword, are used to change/modify the data type of any specific column.