mysql 使用技巧 分页limit

mysql 使用技巧 分页limitmysql 分页使用 limit关键字,limit x,y (x代表从哪条数据开始,y代表页面大小。mysql第一条数据在limit计算时索引为0) limit 10 前10条 limit 0,10

mysql 使用技巧 分页limit

mysql 分页使用 limit关键字,limit x,y (x代表从哪条数据开始,y代表页面大小。mysql第一条数据在limit计算时索引为0)

代码100分

代码100分limit 10
  前10条
limit 0,10
  从第1条开始的10条
limit 10,10
  从第 11 条开始的 10 条
limit 100,10
  从第101条开始的10条
  数据量大时(>千万),效率低
oracal 分页,使用 oracle的特殊列 rownum
select * from (select *,rownum R from (select * from a)

实例:查找入职员工时间排名倒数第三的员工所有信息。limit 2,1代表选择从第3条数据开始的1条数据,即第3页数据,页面大小为1

select * from employees order by hire_date desc limit 2,1

 

前n条数据,即从索引0开始计算:limit n 或者 limit 0,n

代码100分mysql> select * from employees order by hire_date desc limit 5;
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
| employee_id | first_name | last_name | email   | phone_number       | hire_date  | job_id   | salary  | commission_pct | manager_id | department_id |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
|         173 | Sundita    | Kumar     | SKUMAR  | 011.44.1343.329268 | 2000-04-21 | SA_REP   | 6100.00 |           0.10 |        148 |            80 |
|         167 | Amit       | Banda     | ABANDA  | 011.44.1346.729268 | 2000-04-21 | SA_REP   | 6200.00 |           0.10 |        147 |            80 |
|         166 | Sundar     | Ande      | SANDE   | 011.44.1346.629268 | 2000-03-24 | SA_REP   | 6400.00 |           0.10 |        147 |            80 |
|         128 | Steven     | Markle    | SMARKLE | 650.124.1434       | 2000-03-08 | ST_CLERK | 2200.00 |           NULL |        120 |            50 |
|         165 | David      | Lee       | DLEE    | 011.44.1346.529268 | 2000-02-23 | SA_REP   | 6800.00 |           0.10 |        147 |            80 |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
5 rows in set (0.00 sec)

mysql> select * from employees order by hire_date desc limit 0,5;
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
| employee_id | first_name | last_name | email   | phone_number       | hire_date  | job_id   | salary  | commission_pct | manager_id | department_id |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
|         173 | Sundita    | Kumar     | SKUMAR  | 011.44.1343.329268 | 2000-04-21 | SA_REP   | 6100.00 |           0.10 |        148 |            80 |
|         167 | Amit       | Banda     | ABANDA  | 011.44.1346.729268 | 2000-04-21 | SA_REP   | 6200.00 |           0.10 |        147 |            80 |
|         166 | Sundar     | Ande      | SANDE   | 011.44.1346.629268 | 2000-03-24 | SA_REP   | 6400.00 |           0.10 |        147 |            80 |
|         128 | Steven     | Markle    | SMARKLE | 650.124.1434       | 2000-03-08 | ST_CLERK | 2200.00 |           NULL |        120 |            50 |
|         165 | David      | Lee       | DLEE    | 011.44.1346.529268 | 2000-02-23 | SA_REP   | 6800.00 |           0.10 |        147 |            80 |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
5 rows in set (0.00 sec)

 

更多例子 

limit 5     前5条数据
limit 2,1   第3页数据,页面大小为1
limit 2,2   第2页数据,页面大小为2
limit 2,3   第3条数据起,共3条数据,此数据不符合分页数据显示格式
分页显示格式:limit startIndex pageSize
startIndex = (需要查询的页码数 - 1) * pageSize
mysql> select * from employees order by hire_date desc limit 5;
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
| employee_id | first_name | last_name | email   | phone_number       | hire_date  | job_id   | salary  | commission_pct | manager_id | department_id |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
|         173 | Sundita    | Kumar     | SKUMAR  | 011.44.1343.329268 | 2000-04-21 | SA_REP   | 6100.00 |           0.10 |        148 |            80 |
|         167 | Amit       | Banda     | ABANDA  | 011.44.1346.729268 | 2000-04-21 | SA_REP   | 6200.00 |           0.10 |        147 |            80 |
|         166 | Sundar     | Ande      | SANDE   | 011.44.1346.629268 | 2000-03-24 | SA_REP   | 6400.00 |           0.10 |        147 |            80 |
|         128 | Steven     | Markle    | SMARKLE | 650.124.1434       | 2000-03-08 | ST_CLERK | 2200.00 |           NULL |        120 |            50 |
|         165 | David      | Lee       | DLEE    | 011.44.1346.529268 | 2000-02-23 | SA_REP   | 6800.00 |           0.10 |        147 |            80 |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
5 rows in set (0.00 sec)

mysql> select * from employees order by hire_date desc limit 2,1;
+-------------+------------+-----------+-------+--------------------+------------+--------+---------+----------------+------------+---------------+
| employee_id | first_name | last_name | email | phone_number       | hire_date  | job_id | salary  | commission_pct | manager_id | department_id |
+-------------+------------+-----------+-------+--------------------+------------+--------+---------+----------------+------------+---------------+
|         166 | Sundar     | Ande      | SANDE | 011.44.1346.629268 | 2000-03-24 | SA_REP | 6400.00 |           0.10 |        147 |            80 |
+-------------+------------+-----------+-------+--------------------+------------+--------+---------+----------------+------------+---------------+
1 row in set (0.00 sec)

mysql> select * from employees order by hire_date desc limit 2,2;
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
| employee_id | first_name | last_name | email   | phone_number       | hire_date  | job_id   | salary  | commission_pct | manager_id | department_id |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
|         166 | Sundar     | Ande      | SANDE   | 011.44.1346.629268 | 2000-03-24 | SA_REP   | 6400.00 |           0.10 |        147 |            80 |
|         128 | Steven     | Markle    | SMARKLE | 650.124.1434       | 2000-03-08 | ST_CLERK | 2200.00 |           NULL |        120 |            50 |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
2 rows in set (0.00 sec)

mysql> select * from employees order by hire_date desc limit 2,3;
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
| employee_id | first_name | last_name | email   | phone_number       | hire_date  | job_id   | salary  | commission_pct | manager_id | department_id |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
|         166 | Sundar     | Ande      | SANDE   | 011.44.1346.629268 | 2000-03-24 | SA_REP   | 6400.00 |           0.10 |        147 |            80 |
|         128 | Steven     | Markle    | SMARKLE | 650.124.1434       | 2000-03-08 | ST_CLERK | 2200.00 |           NULL |        120 |            50 |
|         165 | David      | Lee       | DLEE    | 011.44.1346.529268 | 2000-02-23 | SA_REP   | 6800.00 |           0.10 |        147 |            80 |
+-------------+------------+-----------+---------+--------------------+------------+----------+---------+----------------+------------+---------------+
3 rows in set (0.00 sec)

 

版权声明:本文内容由互联网用户自发贡献,该文观点仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 举报,一经查实,本站将立刻删除。
转载请注明出处: https://daima100.com/8944.html

(0)
上一篇 2023-02-18
下一篇 2023-02-18

相关推荐

发表回复

您的电子邮箱地址不会被公开。 必填项已用*标注