What is the abbreviation of sql?

What is the abbreviation of sql?

SQL is the abbreviation of English Structured Query Language, which means structured query language. The main function is to establish contact and communicate with various databases. SQL Server is a relational database management system (DBMS) developed and promoted by Microsoft. [Recommended tutorial: MySQL tutorial]

1. Name

SQL is the abbreviation of Structured Query Language.

2. Advantages

1) Non-procedural language

2) Unified language

3) All relational databases The common language

3. System

The data architecture of the SQL database is basically a three-level structure, but the terminology used is different from the traditional relational model terminology. In SQL, the relational schema (schema) is called a "base table"; the storage schema (inner schema) is called a "stored file"; the subschema (external schema) is called a "view" ); tuples are called "rows"; attributes are called "columns". The name is symmetrical such as ^00100009a^:

4. Composition

Before formally learning the SQL language, let us first have a basic understanding of the SQL language and introduce the SQL language. Composition:

1. A SQL database is a collection of tables, which is defined by one or more SQL schemas.

2. A SQL table is composed of a row set. A row is a sequence (set) of columns, and each column and row corresponds to a data item.

3. A table is either a basic table or a view. The basic table is the table actually stored in the database, and the view is the definition of a table composed of several basic tables or other views.

4. A basic table can span one or more storage files, and a storage file can also store one or more basic tables. Each storage file corresponds to a physical file on external storage.

5. Users can use SQL statements to query views and basic tables. From the user's perspective, views and basic tables are the same, there is no difference, they are all relationships (tables).

6.SQL users can be applications or end users. SQL statements can be embedded in host language programs. Host languages ​​include FORTRAN, COBOL, PASCAL, PL/I, C and Ada languages, etc. The SQL user can also be used as a separate user interface for end users in an interactive environment.

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