MariaDB IF() Function
The MariaDB IF() function returns a value if a condition is TRUE, or another value if a condition is FALSE.
Syntax
IF(condition, value_if_true, value_if_false)
Parameters
condition |
Required. Specify the value to test. |
value_if_true |
Required. Specify the value to return if condition is TRUE. |
value_if_false |
Required. Specify the value to return if condition is FALSE. |
Return Value
Returns value based on the condition.
Example 1:
The example below shows the usage of IF() function.
SELECT IF(100>200, "TRUE", "FALSE"); Result: "FALSE" SELECT IF(100<200, "T", "F"); Result: "T" SELECT IF(100<200, 500, 600); Result: 500 SELECT IF(DATE(NULL), 500, 600); Result: 600 SELECT IF('', 500, 600); Result: 600 SELECT IF(ISNULL(NULL), "Replace NULL", "This is not NULL"); Result: Replace NULL
Example 2:
Consider a database table called Product with the following records:
ProductName | Price | StockQuantity | OrderQuantity |
---|---|---|---|
Apple | 1.00 | 100 | 20 |
Banana | 1.25 | 120 | 30 |
Orange | 2.15 | 105 | NULL |
Watermelon | 3.50 | 75 | 15 |
If the OrderQuantity is optional and can contain NULL values. The statement mentioned below will give NULL value.
SELECT *, Price * (StockQuantity + OrderQuantity) AS Inventory FROM Product;
This will produce the result as shown below:
ProductName | Price | StockQuantity | OrderQuantity | Inventory |
---|---|---|---|---|
Apple | 1.00 | 100 | 20 | 120.0 |
Banana | 1.25 | 120 | 30 | 187.5 |
Orange | 2.15 | 105 | NULL | NULL |
Watermelon | 3.50 | 75 | 15 | 315.0 |
To avoid such situations, the IF() function in conjunction with ISNULL() function can be used to provide an alternative value to the column if it contains NULL value.
SELECT *, Price * (StockQuantity + IF(ISNULL(OrderQuantity), 0, OrderQuantity) AS Inventory FROM Product;
This will produce the result as shown below:
ProductName | Price | StockQuantity | OrderQuantity | Inventory |
---|---|---|---|---|
Apple | 1.00 | 100 | 20 | 120.0 |
Banana | 1.25 | 120 | 30 | 187.5 |
Orange | 2.15 | 105 | NULL | 225.75 |
Watermelon | 3.50 | 75 | 15 | 315.0 |
❮ MariaDB Functions