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I believe that many inexperienced people don't know what to do about the operation of ADO objects and the functions of main objects in ADO. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

ADO (ActiveXDataObjects) is a new type of data access interface provided and recommended by Microsoft, which is implemented as Automation. In this way, programmers can easily access Automation objects such as VisualBasic, VisualC++, VisualJ++ and Delphi in various development environments that support ADO. The following editor will explain the operations of ADO objects? what are the functions of the main objects in ADO?

What are the operations of the ADO object

The main operations on ADO objects are basically the same as the implementation of DAO and RDO libraries. It mainly includes six aspects:

1. Connect to the data source. This is an optional Connection object that usually involves ADO.

two。 Submit a command to the data source. The Command object of ADO is usually involved. It can be used in conjunction with parameter objects (Parameter) in queries.

3. Execute commands, such as a SELECT script.

4. If the submitted command returns a result, you can manipulate the result through the Recordset object of ADO, and the data is stored in the cache.

5. If appropriate, the modified data in the cache can be updated to the physical storage.

6. Provides error detection. The Error object of ADO is usually involved.

From the programmer's point of view, the object names of ADO, DAO, and RDO are different. But using ADO objects is much easier than DAO and RDO. The most important point is that programmers do not have to create sub-objects step by step from the top level of the object model as they do with DAO and RDO. As a result, ADO provides a more flexible way of programming.

What are the functions of the main objects in ADO

A Connection object that represents a session to a data source. Using members of the Connection object, you can use the appropriate properties to open a connection to the data source, set the location of the cursor, set the default current database, set the OLEDBProvider to be used, submit the SQL script directly, and so on. It is worth noting that when submitting the task of a SQL script, the query can be completed without creating a Command object. In addition, the creation of Connection objects is independent of other objects. The Command object, which can be used to query the database and return the results in the Recordset object. You can also batch and manipulate the structure of the database, which, of course, needs to be supported by the OLEDBProvider used. In addition, an active Connection object can be bound to the ActiveConnection property of the Command object, which allows multiple instances of the Command object to share a Connection object.

The Recordset object, which encapsulates the results of a query, can be called a result set.

The Field object, which is used to express the type and value of each subsegment in a row of results.

Error object, which is used to detect and judge errors in database operations, such as connection failures. In ADO, many objects have an "s" after their names, such as Error- > Errors,Field- > Fields, and so on. Adding "s" means that it is the Collection object of the corresponding object, for example, Errors is the Collection object of the Error object. Collection is a bit like an Array, but the difference is that Collection can take different types of data or objects as its own elements, and the elements in an array are usually of the same type. So, when you see an object name ending with "s", it usually indicates that this is a Collection object, for example, the elements in Errors are made up of instances of the Error object.

After reading the above, have you mastered the operations of ADO objects and the functions of the main objects in ADO? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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