SQL FIRST() Function

在FIRST()函数

的FIRST()函数返回所选列的第一个值。

SELECT FIRST(column_name) FROM table_name;

Note:在FIRST()函数仅在支持Access。

SELECT TOP 1 column_name FROM table_name
ORDER BY column_name ASC;

SELECT TOP 1 CustomerName FROM Customers
ORDER BY CustomerID ASC;

SELECT column_name FROM table_name
ORDER BY column_name ASC
LIMIT 1;

SELECT CustomerName FROM Customers
ORDER BY CustomerID ASC
LIMIT 1;

SELECT column_name FROM table_name
WHERE ROWNUM <=1
ORDER BY column_name ASC;

SELECT CustomerName FROM Customers
WHERE ROWNUM <=1
ORDER BY CustomerID ASC;

在本教程中，我们将使用众所周知的Northwind示例数据库。

下面是从选择"Customers"表：

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
1	Alfreds Futterkiste	Maria Anders	Obere Str. 57	Berlin	12209	Germany
2	Ana Trujillo Emparedados y helados	Ana Trujillo	Avda. de la Constitucion 2222	Mexico D.F.	05021	Mexico
3	Antonio Moreno Taqueria	Antonio Moreno	Mataderos 2312	Mexico D.F.	05023	Mexico
4	Around the Horn	Thomas Hardy	120 Hanover Sq.	London	WA1 1DP	UK
5	Berglunds snabbkop	Christina Berglund	Berguvsvagen 8	Lulea	S-958 22	Sweden

下面的SQL语句选择的第一价值"CustomerName"从列"Customers"表：

SELECT FIRST(CustomerName) AS FirstCustomer FROM Customers;