获取当前文件上一条与下一条记录的原理是上一条的sql语句,从news表里按从大到小的顺序选择一条比当前ID小的新闻,下一条的sql语句,从news表里按从小到大的顺序选择一条比当前ID大的新闻。
mssqlserver查询方法
其实我做了最简的就是如下写法
代码如下 | 复制代码 |
上一条记录的SQL语句: top 1 * from news where newsid 下一条记录的SQL语句: select top 1 * from news where newsid>id order by newsid ASC |
另一种写未能
id是指当前数据news_id参数
方法一:
代码如下 | 复制代码 |
string nextSql = "select top 1 * from news where news_id > " + id + " order by news_id ASC" |
方法二:
代码如下 | 复制代码 |
|
mysql查询上一条与下一条的办法
如果ID是主键或者有索引,可以直接查找:
方法1:
代码如下 | 复制代码 |
1.select * from table_a where id = (select id from table_a where id 2.select * from table_a where id = (select id from table_a where id > {$id} order by id asc limit 1); |
方法2:
代码如下 | 复制代码 |
1.select * from table_a where id = (select max(id) from table_a where id 2.select * from table_a where id = (select min(id) from table_a where id > {$id}); |
其他更优的暂时还没想出来

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MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen

MySQL is suitable for small and large enterprises. 1) Small businesses can use MySQL for basic data management, such as storing customer information. 2) Large enterprises can use MySQL to process massive data and complex business logic to optimize query performance and transaction processing.

InnoDB effectively prevents phantom reading through Next-KeyLocking mechanism. 1) Next-KeyLocking combines row lock and gap lock to lock records and their gaps to prevent new records from being inserted. 2) In practical applications, by optimizing query and adjusting isolation levels, lock competition can be reduced and concurrency performance can be improved.


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