Have you ever written SQL and thought, 'Wait, the count doesn't match' or 'The condition isn't working'? Often, the cause lies in how NULL is handled. NULL is a special entity in SQL, and using it ...

Find the average scores of the customers. Uses COALESCE to replace NULL Score with 0.

NULL in SQL is a powerful concept, representing the absence of a value. It’s used when data is unavailable or unknown, but its usage requires careful consideration. The first step is understanding the ...

Controls whether concatenation results are treated as null or empty string values. If SET CONCAT_NULL_YIELDS_NULL is not specified, the setting of the CONCAT_NULL_YIELDS_NULL database option applies.