SQL queries the previous and next records of the current data

The principle of obtaining the previous and next records of the current file is the previous SQL statement. in the news table, select a news item and the next SQL statement in the order of size to size, select a news item that is larger than the current ID from the news table in ascending order.

The principle of obtaining the previous and next records of the current file is the previous SQL statement. in the news table, select a news item and the next SQL statement in the order of size to size, select a news item that is larger than the current ID from the news table in ascending order.

Mssqlserver query method

In fact, the simplest way is to write the following code:

The code is as follows:
SQL statement of the previous record: Top 1 * from news where newsid The SQL statement of the next record: Select top 1 * from news where newsid> id order by newsid ASC

Another write failure

Id indicates the news_id parameter of the current data.

Method 1:

The code is as follows:
String preSql = "select top 1 * from news where news_id <" + id + "order by news_id DESC" String nextSql = "select top 1 * from news where news_id>" + id + "order by news_id ASC"

Method 2:

The code is as follows:
String preSql = "select * from [news] where news_id = (select MAX (news_id) from [news] where news_id <" + id + ")"; String nextSql = "select * from [news] where news_id = (select MIN (news_id) from [news] where news_id>" + id + ")";

Mysql Query method

If the ID is a primary key or has an index, you can directly find it:
Method 1:

The code is as follows:
1. select * from table_a where id = (select id from table_a where id <{$ id} order by id desc limit 1 ); 2. select * from table_a where id = (select id from table_a where id> {$ id} order by id asc limit 1 );

Method 2:

The code is as follows:
1. select * from table_a where id = (select max (id) from table_a where id <{$ id }); 2. select * from table_a where id = (select min (id) from table_a where id >{$ id });

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