JDBC presentations (2)
JDBC presentations (2)
2.3. JDBC must be able to build on existing database interface
We must be able to guarantee JDBC SQL API can be established in the ordinary SQL API, in particular, ODBC. These requirements have some parts of this standard have had an impact, especially onä¼ å‡ºparameter (OUT parameter) and the handling of large data blocks.
2.4. Must ensure that the interface with the rest of the Java System line
JAVA present a positive response has been very encouraging. This is largely due to language standards, as well as the standard run-time library is considered consistent, simple and powerful. We will do everything we can to provide the Java database interface, the interface will be built on existing Java core of this style, and will further strengthen it.
2.5. Remain simple
We would prefer to keep this base API as simple as possible, at least initially. In general we would prefer to provide a single mechanism for performing a particular task, and avoid provid-ing duplicate mechanisms. We will extend the API later if any important functionality is miss-ing.
We will strive to make basic API as simple as possible, at least at the beginning of the case. Generally speaking, we hope to achieve each specific task only provide a programme, and provide a wide range of programmes to avoid. If the omission of some important function, and then we will be expanded later this API.
2.6. To maintain strong, the type of static
We hope that this JDBC API to maintain the strong type checking, making as much as possible the types of information can be static expression. To make as many errors at compile time can be found.
Because SQL itself is dynamic typing, so we may be encountered when operating procedures can not match the types of problems. For example: When a programmer in the hope of SELECT return an integer, but the actual return is a string "foo." However, we still hope that the programmers they want the type at compile time will be able to express clearly, so that we can do The static check as much as possible. We also hope that the necessary time to support dynamic typing interface (see Chapter IV)
2.7. Simplify the task of the ordinary
We hope that the ordinary can be a simple task, the work is generally not feasible.
Is a common task of a programmer to implement a simple SQL statement without parameters (such as: SELECT, INSERT, UPDATE, DELETE), and then (eg SELECT) deal with the return of a simple type of element group. An imported parameters (IN parameter) SQL statement is also common.
But not so ordinary circumstances it is important that when programmers use INOUT, OUT parameters of the SQL statement. We also need to support literacy Jizhao byte object SQL statements, especially some of the cases include a return of a number of results statements set.
We hope that the metadata (Meatdata) the use of small, but those skilled programmers, as well as development tools it needs to deal with. Metadata access function and dynamic types of data access function in this end of a document, the general programmers can not care about these chapters.
2.8. Different functions to different methods (functions) to achieve ( "method", which read: method, this translation is with the VB)
Interface design style is a little use of the process, providing many of the transmission parameters of the control signs, so that they can be used to great influence within the scope of a variety of acts. To express different functions. This trend and use many ways, but each method are more understanding of consent.
Generally speaking, the core Java class using different methods (method). The main advantage of this step is the beginning of learning basic interface for programmers who can not be associated with the function of the parameters of complex troubled by. We have sought in the JDBC interface has also adopted the same strategy. Generally speaking a different approach rather than a different signs and the versatility of the method.
(To be continued)
