最近在學w3schools上面的SQL教程，整理了一些關於SQL的基礎知識。

一、初識SQL

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

SQL 是一種連線和使用資料庫的標準化查詢語言。

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

不同資料庫的查詢語言略有不同。

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語句的關鍵字不區分大小寫，但是使用大寫的比較常見。

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.

在每一個SQL語句句末新增分號，是區分不同SQL命令的標準做法。