How to use GREATEST() Function In SQL

Finding the Maximum Value Among Multiple Columns in PostgreSQL

Before we delve deeper into the queries, let us start by creating the table and inserting some sample values in the table. The following code creates the Sample Table and inserts four entries in the table....

Method 1: Using CASE expression

The CASE expression allows the user to write conditions much like if-else or switch statements in PostgreSQL. We can use this to create condition when one column is greater than every other....

Method 2: Using GREATEST() Function

The GREATEST() function returns the maximum value of all the arguments with the number of arguments can be anything. So using the GREATEST() function we can compare literal values as well as columns....

Example of Find the Maximum of Multiple Columns

Let’s now use the concepts we have learned in this article in a technical example....

Conclusion

In this article, we covered how we can find the maximum of multiple columns in PostgreSQL. We had a chance to look at two different methods to go about doing this, first using CASE statement. We understood the pitfalls of the CASE statement and how quickly it can get very complicated. We later looked at the GREATEST() function and understood the ease it provides. We also how we can use the concepts we learned in this article to a real-life situation through the technical example....