Can we compare NULL values in Oracle?

Nulls with Comparison Conditions Because null represents a lack of data, a null cannot be equal or unequal to any value or to another null. However, Oracle considers two nulls to be equal when evaluating a DECODE function.

Can we compare NULL values in SQL?

In SQL Server, NULL value indicates an unavailable or unassigned value. Because the NULL value cannot be equal or unequal to any value, you cannot perform any comparison on this value by using operators such as ‘=’ or ‘<>’.

How does Oracle handle null values?

  1. Background. Most of the examples in this article require the following table.
  2. NVL. The NVL function allows you to replace null values with a default value.
  3. DECODE.
  4. NVL2.
  6. NULLIF.
  7. LNNVL.
  8. NANVL.

Can null be compared?

Therefore NULL is neither equal to a value nor unequal to it, so any comparison involving NULL is neither true nor false. The result of a comparison involving NULL is not a boolean value—it is a non-value. You just can’t compare something that exists with something that doesn’t exist.

What is the full meaning of NULL?

Null means having no value; in other words null is zero, like if you put so little sugar in your coffee that it’s practically null. Null also means invalid, or having no binding force. From the Latin nullus, meaning “not any,” poor, powerless null is not actually there at all.

Is NULL equal to NULL in Oracle?

One of the most mindboggling values in the Oracle database is the NULL value. NULL is not even the same as NULL. NULL is undefined. But you need to work with NULL values (which are no actual values).

IS NULL is equal to 0?

A null character is a byte which has all its bits set to 0. pointer context – NULL is used and means the value of the pointer is 0, independent of whether it is 32bit or 64bit (one case 4 bytes the other 8 bytes of zeroes).

IS NULL replace Oracle?

The Oracle NVL() function allows you to replace null with a more meaningful alternative in the results of a query. The NVL() function accepts two arguments. If e1 evaluates to null, then NVL() function returns e2 . If e1 evaluates to non-null, the NVL() function returns e1 .

Is null or empty SQL?

NULL is used in SQL to indicate that a value doesn’t exist in the database. It’s not to be confused with an empty string or a zero value. While NULL indicates the absence of a value, the empty string and zero both represent actual values.