最近在学w3schools上面的SQL教程，整理了一些关于SQL的基础知识。

一、初识SQL

SQL stands for Structured Query Language.
SQL is a standard language for accessing and manipulating databases.

SQL 是一种连接和使用数据库的标准化查询语言。

Although SQL is an ANSI (American National Standards Institute) standard, there are different versions of the SQL language.

不同数据库的查询语言略有不同。

RDBMS stands for Relational Database Management System.

RDBMS is the basis for SQL, and for all modern database systems such as MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access.

The data in RDBMS is stored in database objects called tables.

A table is a collection of related data entries and it consists of columns and rows.

二、注意

SQL keywords are NOT case sensitive: select is the same as SELECT

SQL语句的关键字不区分大小写，但是使用大写的比较常见。

Semicolon is the standard way to separate each SQL statement in database systems that allow more than one SQL statement to be executed in the same call to the server.

在每一个SQL语句句末添加分号，是区分不同SQL命令的标准做法。