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This article will explain in detail whether sql is the standard language of hierarchical database. The editor thinks it is very practical, so I share it with you as a reference. I hope you can get something after reading this article.

Sql is not the standard language of hierarchical database, but the standard language of relational database. Structured query language SQL is a comprehensive, universal and powerful relational database language, which is used to access data and query, update and manage relational database systems.

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.

Structured query language 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. Structured query language statements can be nested, which makes it have great flexibility and powerful functions.

Functionally, SQL can be divided into three parts: data definition, data manipulation and data control.

The core part of SQL is equivalent to relational algebra, but it has many characteristics that relational algebra does not have, such as aggregation, database update and so on. It is a comprehensive, universal and highly functional relational database language. Its characteristics are as follows:

1. Data description, manipulation, control and other functions are integrated.

2. Two ways of use and unified grammatical structure. SQL can be used in two ways. One is online interactive use, in which SQL is actually used as a self-contained language. Another way is to embed it into a high-level programming language (such as C, etc.). The former method is suitable for non-computer professionals, and the latter is suitable for computer professionals. Although it is not used in the right way, the grammatical structure of the language is basically the same.

3. Highly non-procedural. SQL is a fourth generation language (4GL), users only need to put forward "what to do", do not need to specify "how to do", such as access path selection and specific processing operations are automatically completed by the system.

4. The language is concise and easy to learn and use. Although SQL is very powerful, the language is very concise, and only nine verbs are used in the core function. The grammar of SQL is close to spoken English, so it is easy for users to learn and use it.

This is the end of this article on whether sql is the standard language of hierarchical database. I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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