LENGTH Function - SQL

Overview

The LENGTH function in SQL returns the number of characters in a given string. It is useful for determining the length of a string.

Example:

SELECT LENGTH('Hello')

Syntax:

SELECT LENGTH(string_expression)

string_expression is the string for which you want to determine the number of characters.

Sample Data:

    
            department_id
            first_name
        
            3
            Frank
        
            2
            Jane
        
            3
            Ashley
        
            NULL
            Glenn
        
            2
            Kelly
        
            1
            Richard
        
            1
            George
        
            5
            Kyle
        
            2
            James
        
            1
            Gustavo

department_id	first_name
3	Frank
2	Jane
3	Ashley
NULL	Glenn
2	Kelly
1	Richard
1	George
5	Kyle
2	James
1	Gustavo

Example: Hard-coded value

In this example, we are returning the number of characters in the string ‘Hello’ and the final output is 5.

Example: Query without the WHERE Statement

In this example, we are returning the number of characters that is in each value of the first_name column. The first name is ‘Frank’ and you can see that the first output is 5.

Example: Query with the WHERE Statement

In this example, we are returning the number of characters that is in each value of the first_name column where the department_id equals 1. The first name on the list with a department_id of 1 is ‘Richard’ and the first output on the list equals 7.