JDBC SQLite [SQLITE_ERROR] SQL error or missing database (no such table: MyTable), but it's existed

I have table name 'MyTable' in SQLite database QL3.db. The database URL is right, I can connect to it at "DB_URL = "jdbc:sqlite:\DB\QL3.db";

When I try to access MyTable (existed), I get error message "[SQLITE_ERROR] SQL error or missing database (no such table: MyTable)", though it's existed