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This article mainly introduces what the database objects are, which can be used for reference. Interested friends can refer to them. I hope you will gain a lot after reading this article.

Database objects include: users (people who have access to the database), views (showing data items that users need), indexes (providing users with a quick way to access data), triggers (a set of user-defined SQL transaction commands), sequences (sequential tables that provide unique values), charts (a diagram of the relationship between database tables).

The main database objects are

User (User)

In fact, a user refers to a person who has access to the database.

View (View)

The view also has a set of data items and named fields, which only appear when the user performs the query operation, but does not exist in the database. By controlling the user's access to the data, the data is simplified and only the data items needed by the user are displayed.

Index (Index)

Index is to provide users with a way to quickly access data, always supervise the data of database tables, so as to establish an order with reference to specific database table columns, mainly in order to facilitate users to access specified data and avoid data duplication.

Trigger (Trigger)

Triggers, which belong to a collection of user-defined SQL transaction commands in a database table. If you delete, insert, or modify a database table, the command can be executed automatically.

Sequence

Sequences, definitions are stored in data dictionaries, and sequences provide a sequential table of unique values to simplify program design.

Chart (Diagram)

A chart is to edit the relationship between tables and tables, which can be understood as a diagram of the relationship between database tables.

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