数据库教程-mariadb教程-MariaDB限制返回记录

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在MariaDB数据库中,使用SELECT语句和LIMIT子句从表中检索一个或多个记录。

语法:

SELECT expressions   FROM tables   [WHERE conditions]   [ORDER BY expression [ ASC | DESC ]]   LIMIT row_count; 

示例1:

以降序检索记录:

使用SELECT语句并带有LIMIT子句查询students表中的数据。结果student_id列的值按降序显示,LIMIT3。参考如下语句 –

SELECT student_id, student_name, student_address   FROM Students   WHERE student_id <= 7   ORDER BY student_id DESC   LIMIT 3; 

执行上面查询语句,得到以下结果 –

MariaDB [testdb]> SELECT student_id, student_name, student_address     -> FROM Students     -> WHERE student_id <= 7     -> ORDER BY student_id DESC     -> LIMIT 3; +------------+--------------+-----------------+ | student_id | student_name | student_address | +------------+--------------+-----------------+ |          6 | Blaba        | Shengzheng      | |          5 | Kobe         | Shanghai        | |          4 | Mahesh       | Guangzhou       | +------------+--------------+-----------------+ 3 rows in set (0.00 sec) 

示例2:

student_id列的值升序检索记录:

SELECT student_id, student_name, student_address   FROM Students   WHERE student_id <= 7   ORDER BY student_id ASC   LIMIT 3; 

执行上面查询语句,得到以下结果 –

MariaDB [testdb]> SELECT student_id, student_name, student_address     -> FROM Students     -> WHERE student_id <= 7     -> ORDER BY student_id ASC     -> LIMIT 3; +------------+--------------+-----------------+ | student_id | student_name | student_address | +------------+--------------+-----------------+ |          1 | Maxsu        | Haikou          | |          3 | JMaster      | Beijing         | |          4 | Mahesh       | Guangzhou       | +------------+--------------+-----------------+ 3 rows in set (0.00 sec) 

示例3:分页

在应用程序中,由于数据记录太多,不能全在一个页面中全部显示,我们经常要使用分页来显示。假设每页显示3条记录,参考以下语句 –

-- 第1页数据 SELECT student_id, student_name, student_address   FROM Students   WHERE student_id > 0  ORDER BY student_id ASC   LIMIT 0,3;   -- 第2页数据 SELECT student_id, student_name, student_address   FROM Students   WHERE student_id > 0  ORDER BY student_id ASC   LIMIT 3,3;   -- 第3页数据 SELECT student_id, student_name, student_address   FROM Students   WHERE student_id > 0  ORDER BY student_id ASC   LIMIT 6,3; 

执行上面查询语句,得到以下结果 –

MariaDB [testdb]> SELECT student_id, student_name, student_address     -> FROM Students     -> WHERE student_id > 0     -> ORDER BY student_id ASC     -> LIMIT 0,3; +------------+--------------+-----------------+ | student_id | student_name | student_address | +------------+--------------+-----------------+ |          1 | Maxsu        | Haikou          | |          3 | JMaster      | Beijing         | |          4 | Mahesh       | Guangzhou       | +------------+--------------+-----------------+ 3 rows in set (0.05 sec)  MariaDB [testdb]> SELECT student_id, student_name, student_address     -> FROM Students     -> WHERE student_id > 0     -> ORDER BY student_id ASC     -> LIMIT 3,3; +------------+--------------+-----------------+ | student_id | student_name | student_address | +------------+--------------+-----------------+ |          5 | Kobe         | Shanghai        | |          6 | Blaba        | Shengzheng      | +------------+--------------+-----------------+ 2 rows in set (0.00 sec)  MariaDB [testdb]> 

  

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