Table of Contents for

MySQL in a Nutshell, 2nd Edition

Use this function to treat strings in their binary state. This function is useful for making SQL statements case-sensitive. Notice that the syntax does not call for parentheses:

SELECT student_id, name_last
FROM students
WHERE BINARY LEFT(UCASE(name_last), 1) <>
   LEFT(name_last, 1);

+------------+-----------+
| student_id | name_last |
+------------+-----------+
|  433302000 | dyer      |
|  434016005 | de Vitto  |
+------------+-----------+

This statement checks for any student whose last name starts with a lowercase letter. Each student’s last name is converted to uppercase letters, and then the first letter starting from the left is extracted to be compared with the first letter of the last name without case conversion. The results show one record that is probably a typing error and a second that is probably correct. Notice that the BINARY keyword is specified before the comparison is made between the strings, and is applied to both strings.