The LENGTH() function is used to find the length of a string, i.e., the number of characters in a given string. It accepts a string as a parameter. Syntax of the length function is illustrated below:
The input type is a string, and the return type is int, as it returns the number of characters.
- If a null value is passed in the function, i.e., LENGTH(NULL), it will return NULL.
- If the parameter is an empty string LENGTH("), it will return 0.
- If the parameter is a space character LENGTH(''), not empty or null, it will return 1 as it is not empty anymore.
The below example uses the LENGTH() function to find out the length of a string text:
The final output will be as follows:
Let's see how the LENGTH() function works on the personal_details table containing the employee's id, first_name, last_name, and gender of a retail store as columns.
The above query will show the following table:
The following query returns the last name and the length of the last name from the personal_details table, where the length of the last_name is greater than 5.
The output displays all those items in the last_name column with a length of more than 5 characters.