SQL LAST() 函数
LAST() 函数
LAST() 函数返回指定的列中最后一个记录的值。
SQL LAST() 语法
SELECT LAST(column_name) FROM table_name;
注释:只有 MS Access 支持 LAST() 函数。
SQL Server、MySQL 和 Oracle 中的 SQL LAST() 工作区
SQL Server 语法
SELECT TOP 1 column_name
FROM table_name
ORDER BY column_name DESC;
ORDER BY column_name DESC;
实例
SELECT TOP 1 CustomerName FROM Customers
ORDER BY CustomerID DESC;
ORDER BY CustomerID DESC;
MySQL 语法
SELECT column_name FROM table_name
ORDER BY column_name DESC
LIMIT 1;
ORDER BY column_name DESC
LIMIT 1;
实例
SELECT CustomerName FROM Customers
ORDER BY CustomerID DESC
LIMIT 1;
ORDER BY CustomerID DESC
LIMIT 1;
Oracle 语法
SELECT column_name FROM table_name
ORDER BY column_name DESC
WHERE ROWNUM <=1;
ORDER BY column_name DESC
WHERE ROWNUM <=1;
实例
SELECT CustomerName FROM Customers
ORDER BY CustomerID DESC
WHERE ROWNUM <=1;
ORDER BY CustomerID DESC
WHERE ROWNUM <=1;
演示数据库
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 |
SQL LAST() Example
下面的 SQL 语句选取 "Customers" 表的 "CustomerName" 列中最后一个记录的值:
实例
SELECT LAST(CustomerName) AS LastCustomer FROM Customers;