Postgres and Open Source Experts

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.

To find the factorial of a number in PostgreSQL, we use the FACTORIAL() function that takes a number as an input and returns the value of its factorial.

ENUM_RANGE() is a built-in function in Postgres to manipulate the data having Enum data type. This function returns an array containing all the enumerators for the enum type in the same order as defined.

Enums are useful data types in Postgres that make it much easier to query, sort, and maintain the data and eventually improve data integrity.

To use Postgres image in Docker, run Postgres container using this image. For Docker compose file, define services in compose file and run Postgres container.