Oracle ORA-00911: invalid character

This was the error that bug me for few hours. I wasn't sure what was the exact reason. I google'd it and doesn't seems helpful. Then I tried to trim down my SQL queries, in which by luck, the mystery reveiled.

It was a simple SQL query, selecting all records in the table. I include the semicolon ";" which not supposed to be. After removing it, the error gone and the result were what I want. Posting it here as knowledge-base for reference in future.