结构化查询语言（SQL）是一种标准化的语言，它允许你在数据库上执行操作，如创建项目，读取内容，内容更新和删除条目。
SQL是所有可能会使用几乎任何数据库支持，它允许独立于底层数据库的写入数据库的代码。
SQL> CREATE DATABASE DATABASE_NAME;
SQL> CREATE DATABASE EMP;
SQL> USE DATABASE_NAME
SQL> DROP DATABASE DATABASE_NAME;
SQL> CREATE TABLE table_name
(
column_name column_data_type,
column_name column_data_type,
column_name column_data_type
...
);
SQL> CREATE TABLE Employees ( id INT NOT NULL, age INT NOT NULL, first VARCHAR(255), last VARCHAR(255), PRIMARY KEY ( id ) );
SQL> DROP TABLE table_name;
SQL> INSERT INTO table_name VALUES (column1, column2, ...);
SQL> INSERT INTO Employees VALUES (100, 18, ‘Zara‘, ‘Ali‘);
SQL> SELECT column_name, column_name, ...
FROM table_name
WHERE conditions;
SQL> SELECT first, last, age
FROM Employees
WHERE id = 100;
SQL> UPDATE table_name SET column_name = value, column_name = value, ... WHERE conditions;
WHERE子句可以使用比较操作符例如=，！=，<，>，<=，和>=，以及BETWEEN和LIKE操作符。
SQL> UPDATE Employees SET age=20 WHERE id=100;
SQL> DELETE FROM table_name WHERE conditions;
SQL> DELETE FROM Employees WHERE id=100;
原文：http://www.cnblogs.com/bahcelor/p/6658207.html