如何根據位置而不是 ID 從 MySQL 查詢結果集中檢索特定記錄？

Retrieving Specific Records from a MySQL Query

The task at hand is to retrieve a specific record from a MySQL query resultset, not based on its ID, but by its position within the sorted resultset. For instance, if we want to retrieve the 3rd record from a query with ascending ID ordering, we need a way to offset the query and return only that specific record.

The solution to this problem is the LIMIT clause, which can be used to specify the number of records to retrieve from a query starting at a specific offset. The syntax is as follows:

SELECT * FROM table ORDER BY ID LIMIT n-1,1

In this query, the LIMIT clause has two parameters:

• n-1: The offset to start retrieving records from. By subtracting 1 from the desired record number, we ensure that the query will return the correct record.
• 1: The number of records to retrieve. In this case, we only want to retrieve one record.

For example, to retrieve the 3rd record from a query, we would use the following query:

SELECT * FROM table ORDER BY ID LIMIT 2,1

And to retrieve the 5th record:

SELECT * FROM table ORDER BY ID LIMIT 4,1

This technique allows us to efficiently retrieve specific records from a query without knowing their IDs, making it a versatile solution for various database operations.

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