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

SQL Server 語(yǔ)法

SELECT TOP 1
column_name FROM
table_name
ORDER BY
column_name ASC;

實(shí)例

SELECT TOP 1 name FROM Websites

ORDER BY id ASC;

MySQL 語(yǔ)法

SELECT
column_name FROM
table_name

ORDER BY
column_name ASC

LIMIT 1;

實(shí)例

SELECT name FROM Websites

ORDER BY id ASC

LIMIT 1;

Oracle 語(yǔ)法

SELECT
column_name FROM
table_name

ORDER BY
column_name ASC

WHERE ROWNUM <=1;

實(shí)例

SELECT name FROM Websites

ORDER BY id ASC

WHERE ROWNUM <=1;

演示數(shù)據(jù)庫(kù)

在本教程中，我們將使用 RUNOOB 樣本數(shù)據(jù)庫(kù)。

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(niǎo)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     |
+----+---------------+---------------------------+-------+---------+

SQL FIRST() 實(shí)例

下面的 SQL 語(yǔ)句選取 "Websites" 表的 "name" 列中第一個(gè)記錄的值：

實(shí)例

SELECT name AS FirstSite FROM Websites LIMIT 1;

執(zhí)行以上 SQL 結(jié)果如下所示：