将Case语句中的所有结果放到一行中

case expression:
    when condition1 then result1,
    when condition2 then result2,
    when condition3 then result3,
    ...
    else default_result
end

SELECT CONCAT(
    CASE WHEN condition1 THEN result1 ELSE '' END,
    CASE WHEN condition2 THEN result2 ELSE '' END,
    CASE WHEN condition3 THEN result3 ELSE '' END,
    ...
    CASE WHEN conditionN THEN resultN ELSE '' END
) AS combined_result
FROM table_name;

result = [
    result1 if condition1 else '',
    result2 if condition2 else '',
    result3 if condition3 else '',
    ...
    resultN if conditionN else ''
]