在FIRST()函數
的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;
例
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;
例
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;
例
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: