SQL interchange values for data in a column (such as gender)

The SQL problem encountered while brushing the Leetcode

627. Swap Salary

Given a table salary , such as the one below, which 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 query and no intermediate tem P table.

For example:

| ID | name | sex | Salary | | ----|------|-----|--------|| 1  | A    | m   | 2500   | | 2  | B    | f   | | |   3  | C    | m   | 5500   | | 4  | D | f | |    

After running your query, the above salary table should has the following rows:

| ID | name | sex | Salary | | ----|------|-----|--------|| 1  | A    | f   | 2500   | | 2  | B    | m   | | |   | 3  | C    | f   | 5500   | | 4  | D |    m   | |    

Probably asking for sex in the exchange table.

At first I wanted to use update salary set sex = f when sex = M again with an and and then the result of this implementation should be wrong,

And then just peek at the solution, just know there is a case statement, so record

Update Salary   Set =        Case Sex            when ' m '  Then ' F '          Else ' m '      End

It means that when M,then is set to F,,else, it is set to M

SQL interchange values for data in a column (such as gender)