SQL FIRST() 函數(shù)

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FIRST() 函數(shù)

FIRST() 函數(shù)返回指定的列中第一個記錄的值。

SQL FIRST() 語法

SELECT FIRST(column_name) FROM table_name;

注釋：只有 MS Access 支持 FIRST() 函數(shù)。

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SQL Server、MySQL 和 Oracle 中的 SQL FIRST() 工作區(qū)

SQL Server 語法

SELECT TOP 1
column_name FROM
table_name
ORDER BY
column_name ASC;

實例

SELECT TOP 1 name FROM Websites

ORDER BY id ASC;

MySQL 語法

SELECT
column_name FROM
table_name

ORDER BY
column_name ASC

LIMIT 1;

實例

SELECT name FROM Websites

ORDER BY id ASC

LIMIT 1;

Oracle 語法

SELECT
column_name FROM
table_name

ORDER BY
column_name ASC

WHERE ROWNUM <=1;

實例

SELECT name FROM Websites

ORDER BY id ASC

WHERE ROWNUM <=1;

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演示數(shù)據(jù)庫

在本教程中，我們將使用 RUNOOB 樣本數(shù)據(jù)庫。

下面是選自 "Websites" 表的數(shù)據(jù)：

+----+--------------+---------------------------+-------+---------+
| id | name         | url                       | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1  | Google       | https://www.google.cm/    | 1     | USA     |
| 2  | 淘寶          | https://www.taobao.com/   | 13    | CN      |
| 3  | 菜鳥教程      | http://www.runoob.com/    | 4689  | CN      |
| 4  | 微博          | http://weibo.com/         | 20    | CN      |
| 5  | Facebook     | https://www.facebook.com/ | 3     | USA     |
|  6 | 百度         | https://www.baidu.com/    |     4 | CN      |
|  7 | stackoverflow | http://stackoverflow.com/ |     0 | IND     |
+----+---------------+---------------------------+-------+---------+

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SQL FIRST() 實例

下面的 SQL 語句選取 "Websites" 表的 "name" 列中第一個記錄的值：

實例

SELECT name AS FirstSite FROM Websites LIMIT 1;

執(zhí)行以上 SQL 結果如下所示：

文章標題：創(chuàng)新互聯(lián)MSSQL教程SQLFIRST()函數(shù)
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