Learn how to use the COALESCE function in SQL to return the first non-null value from a list of expressions. See the syntax, an example query, and the result for a table with null values. Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. COALESCE returns the first non-null expr in the expression list. You must specify at least two expressions. If all occurrences of expr evaluate to null, then the function returns null. Oracle Database uses short-circuit evaluation. The database evaluates each expr value and determines whether it is NULL, rather than evaluating all of the expr values before determining whether any of them is NULL. If all occurrences of expr are numeric data type or any nonnumeric data type that can be ... We covered how to use COALESCE() to replace NULL values, how to compute an alternative value, and how to combine COALESCE() with the ROLLUP clause, among other examples.
