How to use rank function in sql

The RANK() function in SQL is used to rank rows in the query result set, assigning a ranking value that represents the relative position of each row in the group or table. Usage: RANK() OVER ([PARTITION BY grouping field] ORDER BY sorting field). Parameters: PARTITION BY grouping field (optional): Group the result set and rank each group separately. ORDER BY sorting field: the column to rank by. Return value: An integer representing the relative ranking of the row.

Usage of RANK() function in SQL

RANK() function is used in SQL to evaluate query results Concentrated rows are ranked. It assigns a ranking value that represents each row's relative position within the group or the entire table.

Usage:

<code class="sql">RANK() OVER ( [PARTITION BY 分组字段] ORDER BY 排序字段)</code>

Parameters:

• PARTITION BY Grouping field: Can select. Group the result set and rank each group separately.
• ORDER BY Sorting field: The column by which the ranking is based.

Return value:

An integer representing the relative ranking of the row.

Example:

Query the sales ranking of each product in the sales table:

<code class="sql">SELECT product_id, product_name,
RANK() OVER (PARTITION BY product_id ORDER BY sales_count DESC) AS sales_rank
FROM sales_table;</code>

Result:

Note:

If rows have the same value, they will have the same rank.
• There may be gaps in the ranking of rows, for example when there are duplicate values.
• RANK() function is similar to DENSE_RANK() function, but the latter does not skip ranking of duplicate values.

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