Pivot in SQL

A relational operator called pivot converts data rows into columns. It can be helpful in instances where it's necessary to compare or summarize multiple data points. The PIVOT function, which is present in the majority of relational database management systems (RDBMS), is used to perform a pivot in SQL. Based on the values in one or more columns, you can aggregate data in a specified fashion using the PIVOT function. This is how it goes: First, choose the columns that will serve as the new table headers in the pivoted table together with the data you wish to pivot. Consider, for illustration, a table of sales information that lists the name of the salesperson, the product sold, and the total amount of sales.

Use the following SQL statement to select the data:

SELECT SalespersonName, Product, SalesAmount FROM Sales_Table;

Next, use the PIVOT function to transform the data. The PIVOT function requires three arguments:

• The data aggregation method (e.g., SUM, AVG, COUNT, etc.) that will be used. The column that will serve as the pivot table's new headings (like Product) The data will be grouped by this column, for example, SalespersonName.

Here's an example SQL statement that uses the PIVOT function to transform the sales data into a pivoted table:

SELECT SalespersonName, [Product1], [Product2], [Product3] FROM ( SELECT SalespersonName, Product, SalesAmount FROM Sales_Table ) AS Source_Table PIVOT ( SUM(SalesAmount) FOR Product IN ([Product1], [Product2], [Product3]) ) AS PivotTable

In this illustration, the data is transformed using the PIVOT function so that each salesperson has their own row and each product has a separate column. The SUM function is also used to aggregate the data so that each column's values indicate the total sales for each salesperson and each product.

SQL pivoting allows you to swiftly and effectively summarise and analyse enormous amounts of data. One can gain fresh insights and spot patterns that may have been concealed in the original data by converting rows of data into columns. The PIVOT function in SQL makes the operation simpler than ever and can be a useful tool for any business intelligence or data analytic professional. It should be noted that the PIVOT operator is unique to SQL Server, and several other RDBMSs, such as Oracle, PostgreSQL, and MySQL, have their own methods for pivoting data.