Using "like" in a C # program to query an Access database query for empty issues

Today, a particularly strange question was discovered during the development process: in Access, when like queries are executed in an Access database, Discovery can query the results, which are performed on the database, select * from kpproj where kpname like ' * Test * ', but the same statement is empty in the C # program, what's the situation?

The problem is really tangled, with previous development experience, like in access to use the * number, but SQL Server Oracle database in the standard%, why not at this time. After searching for information, the last thing we found was a connection to the access driver, which used to be an MDB, a database that was accdb, and then a Win7 64-bit development system, so I can't use "*" here because I have access to the OLE DB driver in my program.       If you are using DAO to access the Access database, you must use "*". discovery is not encountered access on the use of *, so to be based on the actual driver to determine;