How to leverage open-source trade data

List of contents of this article:

• 1,How to leverage open-source trade dataIn the database system, what is the storage process, cursor, trigger
• 2, Database Principle - What are the types of storage processes? What are the characteristics of each?
• 3, The prefixes of system storage procedures and system variables are
• 4, What is the system storage process???
• 5, What are the types of database storage processes?

In the database system, what is the storage process, cursor, trigger

The storage process is an important object in the database. Trigger Trigger is a special type of storage process, which is different from the storage process we introduced earlier.Triggers are mainly executed by triggering events, and storage processes can be directly called by storing the name of the procedure.

The storage process is a collection of SQL statements that have been compiled in advance and stored in the database. If you want to implement the corresponding function, you only need to call this storage process (similar to a function, the input has output parameters).

Storage process: This is generally used for precipitation data. When the data you need to query cannot be found in an sql statement or the query speed of the sql statement is particularly slow. If you want to improve efficiency, you will use the storage process. First, the required data is precipitated into the result table and then directly query the result table. It can improve efficiency.

The storage process can also be regarded as a kind of function, andAnd if the process in the storage process is put into the D layer of the development system, the execution effect is the same.

The differences and connections between database transactions, storage procedures, functions and triggers are as follows: Transaction concept Transaction refers to the set of operations that make up a single logical work unit, either fully executed or completely unexecuted.

The prefixes of the system storage process and the system variable are respectively

The system storage process begins with sp_ and is used for various settings of the system. Get the information. Related management work. 2 Local storage process The storage process created by the user is a storage process created by the user and completed a specific function. In fact, the general storage process refers to the local storage process.

System storage process. The storage process with the prefix sp in the name of the storage process belongs to the system storage process. It is provided by SQLServer itself and can be used to complete some specific functions, such as querying database information, updating the database, etc.

The system storage process is stored in the MASTER database with the prefix SP_.User-customized storage process.

System storage process: The name stored in the master library is prefixed with sp_, which mainly obtains information from the system table to provide support for system administrators to manage SQL Server.

Stored Procedures) is mainly stored in the master database and prefixed with sp_, and the system storage process mainly obtains information from the system table, so as to support system administrators to manage SQL Server.

sp_ begins with the system storage process that comes with SQL Server. Through these storage processes, we can simply manage the database system.

What is the system storage process???

1. Stored Procedure is a set of SQL statements in a large database system to complete specific functions. It is stored in the database and is permanently valid after one compilation. Users specify the name of the storage process and give parameters ( If the storage process has parameters) to execute it.

2. The system storage process is a storage process created by the SQLServer system. Its purpose is to conveniently query information from the system table, or to complete the management tasks related to updating the database table or other system management tasks. The system storage process can be executed in any database.

3. Procedures) is the storage process created by the user in the user database. In fact, the storage process is generally called the local storage process. The storage process created by the user is a storage process created by the user and can complete a specific function (such as querying the data information required by the user).

4. The system storage process can be divided into several categories as shown in the following table. For the whole corresponding table, please enter "System Storage Process" in MSDN to retrieve.The Active Directory storage process is used to register SQL Server instances and SQL Server databases in Microsoft Windows 2000 Active Directory.

5. Stored Procedure is a set of SQL statements in a large database system to complete a specific function, which is compiled and stored in the database. The user specifies the name of the storage process and gives parameters (if the storage procedure has There are parameters) to execute it.

6. System storage process: The name stored in the master library is prefixed with sp_, which mainly obtains information from the system table, so as to provide support for system administrators to manage SQL Server.

What are the types of database storage processes?

1. Stored Procedures) can be divided into the following two types: A. If the local temporary storage process uses the well sign (#) as the first character of its name in the process of creating the storage, the storage process will become a local temporary storage process stored in the tempdb database (for example, CREATE PROCEDURE book_proc ...).

2. The storage process is an important object in the database. Trigger Trigger is a special type of storage process, which is different from the storage process we introduced earlier. Triggers are mainly executed by triggering events, and storage processes can be directly called by storing the name of the procedure.

3. Copy class storage process, for example: sp_addarticle Create a project and add it to the release. This storage process is executed on the publishing database of the publishing server.