MySQL Tutorials - Herong's Tutorial Examples - Version 4.20, by Dr. Herong Yang
What Is SQL?
This section provides a quick introduction of SQL (Structured Query Language), a comptuer language that allows users to interact with RDBMS to define create data structure and manage data instances.
What Is SQL? SQL (Structured Query Language) is a comptuer language that allows users to interact with Relational Database Management Systems (RDBMS) to define data type and structure, and to insert, update or delete data instances.
Usually, an RDBMS system will offer a user interface (UI) to allow you to issue SQL statements to directly operate on the RDBMS system:
User <--> UI <--SQL--> RDBMS <--> Data storage
A typical RDBMS system does also offer Application Programming Interface (API) to allow application programs to use SQL statements to interact with the RDBMS system:
User <--> Application <--SQL--> RDBMS <--> Data storage
SQL is a non-precedural language. Each SQL statement is an individual execution unit, independent of other statements. There is no conditional statements, jumping statements or looping statements to group multiple statements together into a complext execution unit. There is no way to define a procedure of statements, and no procedure call statements.
Last update: 2015.
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