SQL的UPDATE话语无法执行

SQL的UPDATE语句无法执行？
Dim   str   As   String   =   "Update   Dir2   Set   Check   =   '0 '   Where   路径= 'NOW ' "
Dim   mycom   As   New   OleDbCommand(str,   mycon)
mycom.ExecuteNonQuery()

为何上述语句运行出错？(访问mdb文件)

[解决办法]
将 "check " 用 "[] "括住看下
Dim str As String = "Update Dir2 Set [Check] = '0 ' Where 路径= 'NOW ' "