ISNULL in SQL - sql - sql tutorial - learn sql
- In SQL Server, the ISNULL( ) function is used to replace NULL value with another value.
- ISNULL( ) function is available in both SQL Server and MySQL even though they are different.
- For example, if we have the following table,
Table Wikitechy_Sales_Data
Store_Name | Sales |
---|---|
Store A | 300 |
Store B | NULL |
- The following SQL,
SELECT SUM (ISNULL(Sales,100)) FROM Wikitechy_Sales_Data;
- Returns the following result:
SUM (ISNULL(Sales,100))
400
- This is because NULL has been replaced by 100 via the ISNULL function, so the total becomes 300 + 100 = 400.
Tags : sql tutorial , pl sql tutorial , mysql tutorial , oracle tutorial , learn sql , sql server tutorialMySQL:
MySQL:
- In MySQL, the ISNULL( ) function is used to test whether an expression is NULL.
- If the expression is NULL, this function returns 1.
- Otherwise, this function returns 0.
- For example,
- ISNULL(3*3) returns 0
- ISNULL(3/0) returns 1
SQL isnull VS is not null
