Oracle SQL Query to Return Second Column if First Column is Null
There are multiple ways to return a column that is not null out of 2, 3 or more columns. The SQL statements that can be used for this purpose are NVL, NVL2, CASE, and COALESCE
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SQL, Oracle
Example: In the following table called Customers, return only one Phone Number with priority to CellPhone first then DayPhone. Return Cellphone is CellPhone is not Null. If CellPhone is Null, return DayPhone.
| CustomerName | CellPhone | DayPhone |
| Joe Smith | 916-220-4040 | |
| Kevin Brada | 559-230-5454 | |
| Homer Lopez | 559-646-3232 |
NVL
SELECT CustomerName, NVL(CellPhone, DayPhone) as PhoneNumber FROM Customers;
NVL2
SELECT CustomerName, NVL2(CellPhone, CellPhone, DayPhone) as PhoneNumber FROM Customers;
CASE
SELECT CustomerName, CASE WHEN CellPhone IS NULL THEN DayPhone ELSE CellPhone END as PhoneNumber FROM
Customers;
COALESCE
SELECT CustomerName, COALESCE(CellPhone, DayPhone) as PhoneNumber FROM Customers;
All of the above Queries will produce the following result set
| CustomerName | PhoneNumber |
| Joe Smith | 916-220-4040 |
| Kevin Brada | 559-230-5454 |
| Homer Lopez | 559-646-3232 |
Author
W3Courses was launched in 2003 and has been providing information on technology, business, jobs, and health. W3Courses is continuously adding articles to deliver quality information.
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SQL, Oracle
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