the previous blog introduces ODBC and JDBC, and this is a simple introduction to OLE DB. ODBC Summary do not know is not posted on the blog or not on this blog, I look for, no words I add to the time. All right, let's get started.
Reviewbefore, we introduced the basic structure of ODBC and JDBC is the same, that is, the essence of the same. is a unified set of interfaces that access the database, a series of specifications and APIs for database access. The difference is that ODBC is implemented by the C + + language, and JDBC is implemented in Java, because the Java program and the C + + ODBC communication is inconvenient. It can be said that the relationship between ODBC and JDBC is horizontal, whereas OLE DB is vertically relative to ODBC. Why do you say that?
History of OLE DBWhy is it that the relationship between Ole DB (Object linking and Embedding, Database) and ODBC is vertical? This is still to be said from ODBC, ODBC is a set of interfaces, but ODBC only supports access to the relational database, two-dimensional data database. But with the development of technology obviously we need to face not only the relational database, but also the non-relational row and hierarchy row data that cannot be accessed with SQL, including the data in the mail system, the text on the Web, the directory service and so on. Therefore, the relationship between Ole DB and ODBC from the point of view of the data source is as follows:
based on COM standardsODBC is an API-based implementation, while OLE DB is based on COM standards. That is to say, ODBC must support almost all DBMS features and functionality on implementation, while OLE DB can be partially implemented. There's not much to understand. com standards.
OLE DB composition
OLE DB includes several logical components because they are based on COM standards, so the components are independent of each other and only maintain communication.
Data Provider: A database provider that provides the data through OLE DB. The concept of a data provider can be compared with the driver in ODBC.
Data Consumer: A program or component that uses the data provided by OLE DB.
Service Component: Performs data transfer between the data provider and the data consumer.
Business components (bussiness Component): A functional component that can be reused by using a service component to accomplish a particular kind of business-specific processing.
OLE DB and ADOthe previous blog has definitely introduced ADO, here ADO is the further encapsulation of OLE DB, the relationship in the program is as follows:
Overall: OLE db is an extension of ODBC, which is based on COM standards and has a higher flexibility than ODBC. But ultimately it's a set of standards for linking databases. It's just a little lower than the ODBC.
