627. Swap Salary.md

627. Swap Salary

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SQL Schema>

Given a table salary, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f values to m and vice versa) with a single update statement and no intermediate temp table.

Note that you must write a single update statement, DO NOT write any select statement for this problem.

Example:

| id | name | sex | salary |
|----|------|-----|--------|
| 1  | A    | m   | 2500   |
| 2  | B    | f   | 1500   |
| 3  | C    | m   | 5500   |
| 4  | D    | f   | 500    |

After running your update statement, the above salary table should have the following rows:

| id | name | sex | salary |
|----|------|-----|--------|
| 1  | A    | f   | 2500   |
| 2  | B    | m   | 1500   |
| 3  | C    | f   | 5500   |
| 4  | D    | m   | 500    |

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Solution

• Runtime: 243 ms, faster than 67.89%, Memory Usage: 0B, less than 100.00% of MySQL online submissions

  # Write your MySQL query statement below
  update salary set sex= CHAR(ASCII('f') ^ ASCII('m') ^ ASCII(sex));
  

• Runtime: 474 ms, faster than 21.96%, Memory Usage: 0B, less than 100.00% of MySQL online submissions

  # Write your MySQL query statement below
  UPDATE salary
  SET
      sex = CASE sex
          WHEN 'm' THEN 'f'
          ELSE 'm'
      END;