SQL ROW_NUMBER Function Explained

The ROW_NUMBER function is a type of window function that assigns a unique numerical value to each row in a query result set. It is typically used to sort or group query results and assign a consecutive number to each row.

The ROW_NUMBER function creates a new column in the query results that contains a sequential number for each row. The numbering is based on the specified sorting criteria. For example, you can order the rows based on a column’s values and then use the ROW_NUMBER function to assign a number to each row.

The ROW_NUMBER function is commonly used in cases where pagination or filtering of query results is required. By assigning a unique number to each row, it becomes easy to select specific rows or implement pagination features.

Here is an example query that sorts and assigns numbers to the result set using the ROW_NUMBER function.

Choose the row number in the order determined by the column name and display the columns column1 and column2 in a table named table_name.

In the above example, the ROW_NUMBER function sorts the values in the column_name column and assigns a unique number to each row, which is stored in a new column named row_num.