求闭包。数据库中的函数依赖中的闭包和密钥的算法。-Seeking closure. Functional dependencies in the database closure and key algorithm.

使用的依赖包都在压缩包的lib目录下,如果只是需要依赖包,可以直接使用-Use depends on the package are all in the package of the lib directory, if just need to rely on bag, can be used directly