LENGTH / CHAR_LENGTH

LENGTH() (MySQL/PostgreSQL/Oracle) or LEN() (SQL Server) returns how many characters are in a string — useful for validation rules or, here, filtering rows by name length.

Source data — Pattern 3: Built-in Functions

All queries run against the shared employees table (see schema.sql). This pattern needs two columns not used before: hire_date (topic 17) and bonus, nullable (topics 19–20).

LENGTH / CHAR_LENGTH — source table 1

What it does

LENGTH() (MySQL/PostgreSQL/Oracle) or LEN() (SQL Server) returns how many characters are in a string — useful for validation rules or, here, filtering rows by name length. CHAR_LENGTH() is the standard-SQL alias that's explicit about counting characters rather than bytes.

Problem

Find employees whose names contain more than 8 characters.

SELECT first_name,
       last_name,
       LENGTH(CONCAT(first_name, ' ', last_name)) AS name_length
FROM employees
WHERE LENGTH(CONCAT(first_name, ' ', last_name)) > 8;

Result

LENGTH / CHAR_LENGTH — result 1