Difference Between IFNULL() and COALESCE() in MySQL
Both IFNULL() and COALESCE() are used to handle NULL values in MySQL, but they are not identical. They differ in syntax, number of arguments, and behavior.
Takes exactly two arguments.
Returns
expr2only if expr1 is NULL.Otherwise returns
expr1.MySQL-specific function (not part of standard SQL).
Can take two or more arguments.
Returns the first non-NULL value from the list.
Follows standard SQL — more portable across databases.
Arguments: IFNULL() takes only 2; COALESCE() can take many.
Standard vs MySQL-only: COALESCE() is ANSI SQL; IFNULL() is MySQL-specific.
Behavior: COALESCE() returns the first non-NULL in a list; IFNULL() only checks one value.
Performance: IFNULL() can be slightly faster, but the difference is usually negligible.
In summary: Use IFNULL() for simple two-value NULL handling in MySQL, and COALESCE() when you need to check multiple values or want SQL-standard behavior.