What is the Oracle equivalent of SQL Server's IsNull () function?

Question

In SQL Server, we can enter IsNull() to determine if a field is null. Is there an equivalent function in PL / SQL?

Answer 1

coalesce supported in both Oracle and SQL Server and performs essentially the same function as nvl and isnull . (There are several important differences, coalesce can take any number of arguments and returns the first nonzero. The return type for isnull matches the type of the first argument, which is not true for coalesce , at least on SQL Server.)

Answer 2

Instead of ISNULL() use NVL() .

T-SQL:

 SELECT ISNULL(SomeNullableField, 'If null, this value') FROM SomeTable 

PL / SQL:

 SELECT NVL(SomeNullableField, 'If null, this value') FROM SomeTable 

Answer 3

Also use NVL2 as shown below if you want to return another value from field_to_check :

 NVL2( field_to_check, value_if_NOT_null, value_if_null ) 

Usage: ORACLE / PLSQL: NVL2 FUNCTION

Answer 4

You can use the condition if x is not null then... This is not a function. There's also an NVL() function, a good use case here: the NVL ref function .