Summary
ADO and ADO.NET are a strategy for a high-performance access source of Microsoft that allows companies to easily integrate multiple data sources to create easy-to-maintain solutions.
table of Contents
1. Introduction to ADO and ADO.NET
2. The history of data access method
3. ADO & ADO.NET
4. Small knot
1. Introduction to ADO & ADO.NET
ADO and ADO.NET have both similarities and differences. They can write applications for accessing and operation of data in the database server, and are easy to use, high speed, low memory spending, and small disk space, support for establishing Based on the main functionality of applications for client / server and web. But ADO uses OLE DB interfaces and based on Microsoft's COM technology, and ADO.NET has its own ADO.NET interface and based on Microsoft's .NET architecture. It is well known that the NET system is different from the COM system, and the ADO.NET interface is completely different from the ADO and OLE DB interfaces, which means ADO.NET and ADO are two data access methods.
2. The history of data access method
The following is a simple review of several phases of Microsoft's data access methods.
ODBC - (Open Database Connectivity) is the first data access technology that uses SQL access to different relational databases. Using an ODBC application can manipulate different databases through a single command, while developers need to do just to add the appropriate ODBC drivers for different applications.
DAO - (Data Access Objects) is unlike C / C programmers as ODBC, it is a simple data access method for Microsoft to provide Visual Basic developers for manipulating Access databases.
RDO - When using DAO access to different relational databases, the JET engine has to transform the command between DAO and ODBC, resulting in a decline in performance, and the appearance of RDO (Remote Data Objects will be sync.
OLE DB - As more and more data stores in non-relational format, a new architecture requires a seamless connection between the application and data sources, and the OLE DB of CoM (Component Object Model). It is born.
ADO - ADO based on OLE DB is simpler, more advanced, more suitable for Visual Basic programmers, and eliminates the various drawbacks of OLE DB, and instead is the trend of Microsoft's technological development.
3. ADO & ADO.NET
When the design .NET architecture is started, Microsoft decides to redesign the data access model so that it can be fully based on XML and offline calculation models. The differences between the two mainly:
ADO is stored in Recordset, and ADO.NET is represented by a DataSet. Recordset looks more like a single table, if the Recordset must be used in multiple tables in SQL in a multi-table mode. Conversely, the DataSet can be a collection of multiple tables. ADO's operation is an online way, which means that it must be real-time whether it is browsing or updating data. ADO.NET uses offline mode, ADO.NET uses XML to make data, and ADO.NET's database connection is only available online.
Since ADO uses COM technology, this requires the data type used to comply with the COM specification, and ADO.NET is based on XML format, and the data type is more rich and does not need to do Data type conversion caused by COM arrangement, thereby improving overall performance. .
Below is the form of ADO.NET system in the form of charts.
ADO.NET architecture chart
4. Small knot
ADO.NET provides an optimized data access model for the .NET architecture, and COM-based ADO is a complete data access method.
Author: Mengqing Chen
