FIRST() 函数返回指定的列中第一个记录的值。
SELECT FIRST(column_name) FROM table_name;
注释:只有 MS Access 支持 FIRST() 函数。
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
ORDER BY
column_name ASC
WHERE ROWNUM <=1;
SELECT CustomerName FROM Customers
ORDER BY CustomerID ASC
WHERE ROWNUM <=1;
在本教程中,我们将使用众所周知的 Northwind 样本数据库。
下面是选自 "Customers" 表的数据:
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 Constitución 2222 | México D.F. | 05021 | Mexico |
3 | Antonio Moreno Taquería | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
4 | Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
下面的 SQL 语句选取 "Customers" 表的 "CustomerName" 列中第一个记录的值:
SELECT FIRST(CustomerName) AS FirstCustomer FROM Customers;