Two categories: single-layer and multilayer Driver Driver
1. single database driver
Early xBASE driver database system belongs single driver.
Drivers must not only deal with single-ODBC function calls, but also to explain to execute SQL statements, perform database management system (DBMS) function, in fact, he is a Database Management System. Use database applications written it, there are two modes of operation:
Click the environment to run desktop database applications, as shown below
Run File server database applications in the network environment, as shown below:
This database software, such as FoxPro, Access, Paradox and so on.
PS: This application is running in a network environment, the server as a file server used when access to the data, transfers the entire file to the database for processing one host application, the application processing is ended, and then sent to the database server . Drawing file server role only manage user access operations and storage management implementation file.
2. The multi-layered database driver
Such as: the Oracle, Sql Server database driver belongs to a multi-layer driver.
The multilayer driver only processing applications ODBC function calls and data conversion , it passes the SQL statement to the data source, interpreted by the database management system to execute SQL statements, the user's request to implement various operations. Use database applications written in it, is divided into two operating modes of two- and three-tier model:
1. The client / server architecture (commonly known as: C / S), belonging to the two-layer structure
Client-side software: by the application, driver manager, multilayer support database driver and network software.
Server-side software: by the database engine, database, database files, and network support software.
2. The structure of the gateway application (commonly known as: B / S), the three-layer structure
Figure above, the driver receives requests to SQL database gateway, and then transmitted from the database gateway these requests to the database management system.
数据库网关
在Internet/Intranet网络中使用非常普遍，CGI（通用网关接口，即Common Gateway Interface的英文缩写）就是经常使用的一种。如图所示：
