Oracle plsql nvl function

ORACLE/PLSQL: NVL FUNCTION This Oracle tutorial explains how to use the Oracle/PLSQL NVL function with syntax and examples.

DESCRIPTION The Oracle/PLSQL NVL function lets you substitute a value when a null value is encountered.

SYNTAX The syntax for the Oracle/PLSQL NVL function is: NVL( string1, replace_with )

Parameters or Arguments string1 is the string to test for a null value. replace_with is the value returned if string1 is null.

APPLIES TO The NVL function can be used in the following versions of Oracle/PLSQL: Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i, Oracle 8i

EXAMPLE Let's look at some Oracle NVL function examples and explore how to use the NVL function in Oracle/PLSQL. For example: SELECT NVL(supplier_city, '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 supplier_city value.

Another example using the NVL function in Oracle/PLSQL is: SELECT supplier_id, NVL(supplier_desc, supplier_name) FROM suppliers;

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

A final example using the NVL function in Oracle/PLSQL is: SELECT NVL(commission, 0) FROM sales;

This SQL statement would return 0 if the commission field contained a null value. Otherwise, it would return the commission field.

FREQUENTLY ASKED QUESTIONS Question: I tried to use the NVL function through VB to access Oracle DB. To be precise, SELECT NVL(Distinct (emp_name),'AAA'),................

FROM.................

I got an oracle error when I use distinct clause with NVL, but when I remove distinct it works fine.

Answer: It is possible to the use the DISTINCT clause with the NVL function. However, the DISTINCT must come before the use of the NVL function. For example: SELECT distinct NVL(emp_name, 'AAA') FROM employees;

Hope this helps!

Question: Is it possible to use the NVL function with more than one column with the same function call? To be clear, if i need to apply this NVL function to more than one column like this: NVL(column1;column2 ...... , here is the default value for all )

Answer: You will need to make separate NVL function calls for each column. For example: SELECT NVL(table_name, 'not found'), NVL(owner, 'not found') FROM all_tables;