SQL查询根据另一个单元格的值隐藏单个单元格的结果

Question

I am trying to come up with a query where given a table such as below, displays the list of games but hides the answer column for the rows where inProgress = 0.

The only way I can think of is doing a simple query such as SELECT * FROM game WHERE inProgress = 0; is there any other function of SQL that lets me only hide or set the value of the answer column to the desired value where inProgress = 0?

Thanks!

Answer 1

Use a case . It's like an if/else for selecting columns.

select
  gameId,
  case
  when inProgress = 0 then
    null
  else
    answer
  end as answer,
  inProgress
from game

This will show all rows in game but if inProgress = 0 it will not show the answer.

Answer 2

Take a look at MySql case statement. You won't be able to necessarily hide the column, but you could put a value such as N/A or -1 in it to display what you are trying to get across.

SELECT gameId, inProgress, CASE when inProgress = 0 then -1 ELSE answer AS answer FROM game;

Answer 3

A similar but more compact form of a case expression , you could use an inline if

select gameId, if(inProgress = 1, null, answer) Answer, InProgress
from game;