كيف يمكن استخدام NVL2 في كود PL/SQL ، وخصوصاً داخل الديفلوبر ..

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Oracle/PLSQL: NVL2 Function

In Oracle/PLSQL, the NVL2 function extends the functionality found in the NVL function. It lets you substitutes a value when a null value is encountered as well as when a non-null value is encountered.

The syntax for the NVL2 function is:

NVL2( string1, value_if_NOT_null, value_if_null )

string1 is the string to test for a null value.

value_if_NOT_null is the value returned if string1 is not null.

value_if_null is the value returned if string1 is null.

Applies To:

* Oracle 8i, Oracle 9i, Oracle 10g, Oracle 11g


Example #1:

   select NVL2(supplier_city, 'Completed', 'n/a')
   from suppliers;

The SQL statement above would return 'n/a' if the supplier_city field contained a null value. Otherwise, it would return the 'Completed'.

Example #2:

   select supplier_id,
   NVL2(supplier_desc, supplier_name, supplier_name2)
   from suppliers;

This SQL statement would return the supplier_name2 field if the supplier_desc contained a null value. Otherwise, it would return the supplier_name field.