最新的Web開發教程
 

SQL FIRST() Function


FIRST()函數

FIRST()函數返回所選列的第一個值。

SQL FIRST()語法

SELECT FIRST(column_name) FROM table_name;

Note:在FIRST()函數僅在支持Access。


SQL FIRST()解決方法在SQL Server,MySQL和Oracle

SQL Server的語法

SELECT TOP 1 column_name FROM table_name
ORDER BY column_name ASC;

SELECT TOP 1 CustomerName FROM Customers
ORDER BY CustomerID ASC;

MySQL的語法

SELECT column_name FROM table_name
ORDER BY column_name ASC
LIMIT 1;

SELECT CustomerName FROM Customers
ORDER BY CustomerID ASC
LIMIT 1;

Oracle語法

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;

演示數據庫

在本教程中,我們將使用眾所周知的Northwind示例數據庫。

下面是從選擇"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

SQL FIRST()示例

下面的SQL語句選擇的第一價值"CustomerName"從列"Customers"表:

SELECT FIRST(CustomerName) AS FirstCustomer FROM Customers;
試一試»