I. History of data access Methods
Generic data access model:
odbc– (Open Database Connectivity) is an underlying access technology that establishes a set of specifications and provides a set of standard APIs (application programming interfaces) for database access.
OLE db– as more and more data is stored in a non-relational format, a new architecture is needed to provide a seamless connection between this application and the data source, and the OLE DB based on COM (Component Object Model) comes into being.
Data Access client:
DAO-(data access Objects), unlike ODBC, is intended for C + + programmers and is a simple data access method that Microsoft provides to Visual Basic developers for manipulating Access databases.
rdo– when using DAO to access different relational databases, the jet engine had to convert the commands between DAO and ODBC, resulting in degraded performance, and the advent of RDO (Remote Data Objects) was a logical occurrence.
ado–, based on OLE DB, is simpler, more advanced, and more suitable for Visual Basic programmers, while eliminating many of the drawbacks of OLE DB and instead is a trend in Microsoft's technology development.
Ado.net-is a new access programming model. Compared with ADO, it is more universal, not specifically for the design of the database. Ado. NET aggregates all the classes that can be processed.
Ii. ODBC and OLE DB
ODBC is the oldest universal data access technology, but ODBC is limited to retrieving data from relational databases.
The OLE DB provider implements a set of COM interfaces that can handle relational databases and also handle non-relational data.
Third, ADO and
ADO is actually an additional layer at the top of OLE DB (that is, between OLE DB and the application), which encapsulates OLE DB.
Understand the ADO object Model first:
ADO, application, and OLE DB, data provider Contact:
ADO. NET allows any programming language on. NET to connect and access relational and non-relational data, or to stand alone as a type object for processing application data. It is not the next version of ADO, but rather a new architecture that is more powerful and more convenient to use than ADO.
Ado. NET of 5 objects:
The relationship between the individual components:
Iv. Summary:
Each content has its development history, understand every step of its progress, it has a macro control. Then extract their same content, compare their differences, with the old knowledge to solve the new knowledge, more conducive to our understanding.
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Easy to understand ADO, ADO, OLE DB, ODBC