Description

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Implement the missing code, denoted by ellipses. You may not modify the pre-existing code.

You really love counting stuff. In fact, right now you’re sitting on a meadow and counting all the legs you see there! There are some people, some dogs, and some cats on the meadow. You’re pretty confident that each human has 2 legs and that cats and dogs have 4 legs each.

The information about all the creatures on the meadow is stored in the table creatures. It has the following structure:

• id: The unique creature ID;
• name: The creature’s name;
• type: The creature’s type - "human", "cat", or "dog". This column has ENUM type.

You want to calculate the total number of legs in the meadow. Given the table creatures, build a new table that only contains one column summary_legs and has only one row with the total number of legs that you can see.

Example

For the following table creatures

id	name	type
1	Mike	human
2	Misty	cat
3	Max	dog
4	Tiger	human

the output should be

summary_legs
12

There are 2 humans, 1 cat, and 1 dog, so there are 2 _ 2 + 1 _ 4 + 1 \* 4 = 12 legs in total.

• [execution time limit] 10 seconds (mysql)

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DROP PROCEDURE IF EXISTS legsCount;
CREATE PROCEDURE legsCount()
    SELECT SUM(IF(type='human',2,4)) as summary_legs
    FROM creatures
    ORDER BY id;