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FIRST() 函数返回指定的列中第一个记录的值。
SQL FIRST() 语法
SELECT FIRST(column_name) FROM table_name;
注释:只有 MS Access 支持 FIRST() 函数。
SQL Server、MySQL 和 Oracle 中的 SQL FIRST() 工作区
SQL Server 语法
SELECT TOP 1 column_name FROM table_name
ORDER BY column_name ASC;
实例
SELECT TOP 1 CustomerName FROM Customers
ORDER BY CustomerID ASC;
MySQL 语法
SELECT column_name FROM table_name
ORDER BY column_name ASC
LIMIT 1;
实例
SELECT CustomerName FROM Customers
ORDER BY CustomerID ASC
LIMIT 1;
Oracle 语法
SELECT column_name FROM table_name
ORDER BY column_name ASC
WHERE ROWNUM <=1;
实例
SELECT CustomerName FROM Customers
ORDER BY CustomerID ASC
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 FIRST() 实例
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;
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