Collections:
LEAD() - N-Row after Current Row within Window
How to evaluate a field expression on n-row after the current row in the current result set window using the LEAD() function?
✍: FYIcenter.com
LEAD(exp, n, default) is a MySQL built-in window function that
evaluates a field expression on n-row after the current row
in the current result set window.
For example:
SELECT help_topic_id AS tip, help_category_id AS cid, name, LEAD(name, 2, NULL) OVER w FROM mysql.help_topic WINDOW w AS (PARTITION BY help_category_id); -- +-----+-----+----------------+-----------------------------+ -- | tip | cid | name | LEAD(name, 2, NULL) OVER w | -- +-----+-----+----------------+-----------------------------+ -- | 0 | 1 | HELP_DATE | NULL | -- | 1 | 1 | HELP_VERSION | NULL | -- | 2 | 2 | AUTO_INCREMENT | TINYINT | -- | 6 | 2 | BIT | BOOLEAN | -- | 7 | 2 | TINYINT | SMALLINT | -- | 8 | 2 | BOOLEAN | MEDIUMINT | -- | 9 | 2 | SMALLINT | INT | -- | 10 | 2 | MEDIUMINT | INTEGER | -- ... -- +-----+-----+----------------+-----------------------------+
Reference information of the LEAD() function:
LEAD(exp, n, default): val Evaluates a field expression on n-row after the current row in the current result set window. Arguments, return value and availability: exp: Required. The field expression to be evaluated. n: Optional. Default is 1. The number of rows leading the current row. default: Optional. Default is NULL. The default value for non-existing rows. val: Return value. The exp value on n-row after the current row. Available since MySQL 8.
Related MySQL functions:
⇒ NTH_VALUE() - N-th Value of Result Set Window
⇐ LAST_VALUE() - Last Value of Result Set Window
2024-09-28, 2116🔥, 0💬
Popular Posts:
How to download and install Microsoft SQL Server Management Studio Express in SQL Server? Microsoft ...
How To Convert Binary Strings into Hexadecimal Character Strings in SQL Server? When a query returns...
How To Format Time Zone in +/-hh:mm Format in SQL Server Transact-SQL? From the previous tutorial, y...
How to download Microsoft SQL Server 2005 Express Edition in SQL Server? Microsoft SQL Server 2005 E...
Where to find reference information and tutorials on MySQL database functions? I want to know how to...