SQL Server中使用单个case表达式的多列更新

UPDATE 表名
SET 列名1 = CASE
                WHEN 条件1 THEN 值1
                WHEN 条件2 THEN 值2
                ...
                ELSE 值n
            END,
    列名2 = CASE
                WHEN 条件1 THEN 值1
                WHEN 条件2 THEN 值2
                ...
                ELSE 值n
            END,
    ...
WHERE 条件;

UPDATE employees
SET first_name = CASE
                    WHEN employee_id = 1 THEN 'John'
                    WHEN employee_id = 2 THEN 'Jane'
                    ELSE 'Unknown'
                END,
    last_name = CASE
                    WHEN employee_id = 1 THEN 'Doe'
                    WHEN employee_id = 2 THEN 'Smith'
                    ELSE 'Unknown'
                END
WHERE employee_id IN (1, 2);