Array - (PostgreSQL Data Types)

An array data type is a collection of elements of the same data type. In PostgreSQL, arrays can be defined with any built-in or user-defined data type. In this tutorial, we'll explore the array data type in PostgreSQL.

Syntax

data_type[]     -- Array of built-in or user-defined type

Example

Let's create a table that stores an array of integers:

CREATE TABLE example (
   id INTEGER PRIMARY KEY,
   numbers INTEGER[]
);

Now let's insert some data:

INSERT INTO example (id, numbers) VALUES (1, '{1, 2, 3}');
INSERT INTO example (id, numbers) VALUES (2, '{4, 5, 6}');

To retrieve the data from the table, we can use the following query:

SELECT * FROM example;

The output would be:

 id |  numbers   
----+------------
  1 | {1,2,3}
  2 | {4,5,6}

Explanation

In this example, we defined a table with a column of type integer[], which is an array of integers. We inserted some data into the table, where the numbers column is an array of integers. We then retrieved the data from the table using a SELECT statement.

Use

Arrays in PostgreSQL are useful for storing and retrieving multiple values as a single entity. They are commonly used in scenarios where you want to store a list of items, such as a list of tags for an article or a list of dates for an event.

Important Points

• Arrays in PostgreSQL can be multidimensional.
• Arrays can be used in various SQL operations such as SELECT, INSERT, and UPDATE.
• Arrays in PostgreSQL are 0-indexed, meaning the first element is at index 0, the second at index 1, and so on.

Summary

In this tutorial, we discussed the array data type in PostgreSQL. We showed an example of how to create a table with an array column, insert data into the table, and select data from the table. We also covered the use cases and important points of arrays in PostgreSQL. With this knowledge, you can now use arrays in your PostgreSQL database to store and retrieve data more efficiently.