Underscore is a wildcard for a single character. You will need to change your SQL to something like:
WHERE fieldName LIKE '1%'
Or you can escape the underscore
WHERE fieldName LIKE '1\_%'
MySQL starts with searching issue
Underscore is a wildcard for a single character. You will need to change your SQL to something like:
WHERE fieldName LIKE '1%'
Or you can escape the underscore
WHERE fieldName LIKE '1\_%'