基本SQL SELECT语句

SELECT	*|{[DISTINCT] column|expression [alias],...}
FROM	table;

SELECT 标识 选择哪些列。 FROM 标识从哪个表中选择。

2.选择全部列：

SELECT *
FROM   departments;

　　红色的星号代表统配符。

3.选择特定的列：

SELECT department_id, location_id
FROM   departments;

4.使用数学运算符：

SELECT last_name, salary, salary + 300
FROM   employees;

5.操作符优先级：

SELECT last_name, salary, 12*salary+100
FROM   employees;

6.使用别名：

SELECT last_name AS name, commission_pct comm
FROM   employees;