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This article mainly introduces the characteristics of SQL language, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

Sql is a highly non-procedural and collection-oriented operating language. When using SQL for data operation, users only need to propose "what to do" without indicating "how to do", so users do not need to know the access path, the choice of access path and the operation process of SQL statements are automatically completed by the system; SQL adopts set operation mode.

Sql (Structured Query Language, structured query language) is a special purpose programming language. It is a database query and programming language for accessing data and querying, updating and managing relational database systems.

SQL is a high-level non-procedural programming language that allows users to work on high-level data structures. It does not require the user to specify the data storage method, nor does it require the user to know the specific data storage method, so different database systems with completely different underlying structures can use the same structured query language as the interface for data input and management. SQL language statements can be nested, which makes it have great flexibility and powerful functions.

Features of the SQL language:

SQL has a unified style

SQL can independently complete all the activities in the database life cycle, including defining relational schema, entering data, establishing database, query, updating, maintenance, database reconstruction, database security control, etc., which provides a good environment for database application system development. After the database is put into operation, the schema can be modified step by step at any time as needed, and does not affect the operation of the database. So that the system has good expandability.

Highly non-procedural

The data manipulation language of non-relational data model is a process-oriented language, and the access path must be specified when using it to complete user requests. When using SQL for data operation, users only need to propose "what to do" without indicating "how to do". Therefore, users do not need to know the access path, the choice of access path and the operation process of SQL statements are completed automatically by the system. This not only greatly reduces the burden on users, but also helps to improve data independence.

Set-oriented operation mode

SQL adopts set operation mode. Not only the search result can be a collection of tuples, but also the objects of an insert, delete and update operation can also be a collection of tuples.

Provide two ways of use in the same grammatical structure

SQL is both a self-contained language and an embedded language. As a self-contained language, it can be used independently for the use of online interaction, and users can directly input SQL commands on the terminal keyboard to operate the database. As an embedded language, SQL statements can be embedded into programs in high-level languages (such as C, C #, JAVA) for programmers to use when designing programs. In the two different ways of use, the grammatical structure of SQL is basically the same. This provides two different modes of operation with a unified grammatical structure, providing users with great flexibility and convenience.

The language is concise and easy to learn and use.

SQL is extremely powerful, but because of its ingenious design and concise language, only nine verbs are used to complete the core functions of data definition, data manipulation and data control: CREATE, ALTER, DROP, SELECT, INSERT, UPDATE, DELETE, GRANT, REVOKE. And SQL language grammar is simple, close to spoken English, so it is easy to learn and use.

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