Experts in Postgres and Open Source Infrastructure

Exceptions are unexpected issues that we encounter while executing a program code. These disturb and sometimes abort the normal functioning of the program.

To get records from the last 24 hours in Postgres, execute the "SELECT * " command and set a condition to subtract "24 hours" from the current DateTime.

PostgreSQL provides an ASSERT statement for inserting debugging checks for the program. The ASSERT statement provides a condition to the program.

To insert a single quote in the text, we will have to double it up. This makes the text very complex and unreadable in case the string contains many single quotes.

The DDL(Data Definition Language) is used for creating and modifying the object structures in the database using some commands and statements.

To get the first row per group in Postgres, divide the data into groups, assign a number to each row, sort the data in specific order, and retrieve the top row.

Data Manipulation Language, which is basically used to modify the data in a database. The most commonly used commands are INSERT, UPDATE, and DELETE.

INSERT INTO SELECT is a very useful statement in PostgreSQL which allows us to select or copy some data from one table and insert it into another.

Rank() and DENSE_RANK() are the functions used to rank the data. Both functions have some functionality in common and some differences are also there.

Array operators are used to perform different operations on arrays. These operators are used for comparison, containment, overlapping, and concatenation.