Flash cards
Review the key moves
1/4
Core idea
What is the main idea behind MySQL CASE Function?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
1Quick choice
Which statement best captures the main point of this lesson?
2Fill blank
Complete the missing token from the example code.
___ OrderID, Quantity,3Order
Put the learning moves in the order that makes the concept easiest to apply.
The CASE statement goes through conditions and return a value when the first condition is met (like an IF-THEN-ELSE statement).
Definition and Usage
MySQL CASE Function
Example
SELECT OrderID, Quantity,
CASE
WHEN Quantity > 30
THEN "The quantity is greater than 30"
WHEN Quantity =
30 THEN "The quantity is 30"
ELSE "The quantity is
under 30"
END
FROM OrderDetails;Definition and Usage
The CASE statement goes through conditions and return a value when the first condition is met (like an IF-THEN-ELSE statement). So, once a condition is true, it will stop reading and return the result.
If no conditions are true, it will return the value in the ELSE clause.
If there is no ELSE part and no conditions are true, it returns NULL.
Syntax
CASE WHEN
condition1
THEN
result1
WHEN
condition2
THEN
result2
WHEN
conditionN
THEN
resultN
ELSE
result
END;Parameter Values
| Parameter | Description |
|---|---|
| condition1, condition2, ...conditionN | Required. The conditions. These are evaluated in the same order as they are listed |
| result1, result2, ...resultN | Required. The value to return once a condition is true |
Technical Details
| Works in: | From MySQL 4.0 |
|---|