A common case for switching databases is when you deploy a production report server 切换数据库的一个常见示例是部署生产报表服务器。
The following example shows how to switch databases while preserving the original connection options 下面的示例演示了当保留原始连接选项时如何切换数据库。
switching database vendors or trying to cluster the database servers would mean changing all your front end code 转换数据库厂商或设法集群数据库服务器将意味着完全改变您的前端代码。
The good news is that we don t have to change our code if we switch databases, except for the places-such as the use statement and the new statement-where we mention persistent : : mysql by name 令人欣慰的是,除了通过名称来引用persistent::mysql之外(例如use语句和new语句),在切换数据库时不需要更改代码。
I also mention an " obvious " point that needs making : if you suddenly switch databases, the jdbc implementations no longer work unless you modify the code, or use data sources or property files or environment variables as an approach to getting the connection url 我同时也提到了一个需要指出的"显而易见"的问题:如果您突然切换了数据库,那么jdbc实现将不能继续工作(除非您修改了代码,或者使用数据源、属性文件、或环境变量作为获取连接url的方法)。
We analyzed the dependence of equivalent circuit parameters of mesfet switch on material and device structure . for modeling, we designed and fabricated six set of mesfet switches with different gate width, then measured their performance and extracted switch model parameters . mesfet switch database corresponding to the mmic product line is then established, and using the dependence of switch model parameters on gate peripheral we can attain the mesfet switch performance with any gate width through parameters scaling 移相器电路采用gaasmesfet开关作为控制元件,研究了mesfet开关等效电路参数与材料和器件结构参数的关系,设计制作了不同栅宽的六组mesfet开关,并进行参数测试和模型参数提取,建立了相应于mmic工艺线的mesfet开关模型库;根据开关模型参数随栅宽的变化规律,可以实现任意栅宽mesfet开关的参数定标工作。