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How to Get Top N Rows in PostgreSQL

To get the top n rows of a table, the LIMIT clause is used in PostgreSQL. It assists us in getting the subset of rows generated by a query.

PostgreSQL SMALLINT Data Type With Examples

In PostgreSQL, the SMALLINT is used to store small integer values. It takes 2 bytes of storage and can store integers between -32,768 to +32,768.

PostgreSQL VARCHAR Data Type With Examples

VARCHAR(n) or CHARACTER VARYING(n) is a data type in PostgreSQL that stores textual data within a limited range. It can store n number of characters.

How to Show Tables in PostgreSQL?

Execute the “\dt” command from psql tool or use the pg_catalog schema with the aid of the SELECT query from the pgAdmin to show tables of the selected database.

How to Use EXTRACT() Function in PostgreSQL

The EXTRACT() function in PostgreSQL extracts a specific field, like a day, month, minutes, hours, etc., from an INTERVAL or TIMESTAMP.

How to Split a String Using SPLIT_PART() Function in PostgreSQL

PostgreSQL offers a built-in function named SPLIT_PART() that splits the given string based on the specified delimiter. It returns the ‘n’ number of substrings.

How to Use CONCAT Function in PostgreSQL

In PostgreSQL, the CONCAT() function accepts multiple strings as arguments and concatenates them to a single string. Strings can be char, text, or varchar.

How to Use the UNION Clause/Operator in PostgreSQL

In PostgreSQL, the UNION clause/operator combines the result sets of two or more queries. It doesn’t return the duplicated rows in the combined set.

PostgreSQL ROUND() Function With Examples

PostgreSQL provides a built-in function named the ROUND() function that accepts either one or two arguments/values. It rounds a number to the nearest integer.

How to Convert a String to a Number in PostgreSQL

Specify a string followed by “::” and then write the data type to convert the given string into the targeted type like integer, decimal, or double precision.