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How to Use COUNT() Function in PostgreSQL

The table rows can be counted using PostgreSQL's COUNT() function. It is an aggregate function that enables us to count the rows that meet the specified condition. There are multiple ways to use the COUNT() function, such as COUNT(*), COUNT(col_name), and COUNT(DISTINCT col_name). Each implementation of the COUNT() function serves a different functionality.

Let’s learn the working of the COUNT() function through Practical examples.

How to Use COUNT(*) Function in …

How to Use the POSITION() Function in PostgreSQL

In PostgreSQL, to get the substring’s location in a string, the POSITION() function is used. It returns an integer that represents the substring’s location.

How to Use NOT IN Operator in PostgreSQL

In PostgreSQL, the NOT IN operator filters the query results and returns all the values of a result set except the specified values.

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.