MySQL NULL Functions

MySQL NULL Functions

In MySQL, NULL represents the absence of a value. There are several functions to handle NULL values effectively in queries.

🔹 1️⃣ IFNULL()

• Replaces NULL with a specified value.

• Syntax:

Example:

• If marks is NULL, it will return 0.

🔹 2️⃣ ISNULL()

• Checks whether a value is NULL.

• Returns 1 if NULL, otherwise 0.

Example:

🔹 3️⃣ NULLIF()

• Returns NULL if two expressions are equal; otherwise returns the first expression.

• Syntax:

Example:

• If marks = 0, it returns NULL; otherwise, it returns the actual marks.

🔹 4️⃣ COALESCE()

• Returns the first non-NULL value from a list of expressions.

• Syntax:

Example:

• If marks is NULL, it returns 50.

• Can handle multiple fallback values:

🔹 5️⃣ IF() (conditional NULL handling)

• MySQL IF() can also handle NULL indirectly.

• Syntax:

Example:

• Similar effect to IFNULL() but allows more complex conditions.

🔹 Key Points