仅显示一次列值

Question

我有这样的数据：

我想这样显示

所有员工的职位都与经理相同，但我想显示一次。

Answer 1

您可以执行以下操作，但仅应出于显示目的：

WITH a (ename, position, deptno) AS (SELECT 'KING', 'Manager', 10 FROM dual 
                                     UNION ALL 
                                     SELECT 'BLAKE', 'Manager', 30 FROM dual 
                                     UNION ALL 
                                     SELECT 'CLARK', 'Manager', 10 FROM dual 
                                     UNION ALL 
                                     SELECT 'ALLEN', 'Manager', 30 FROM dual 
                                     UNION ALL 
                                     SELECT 'WARD', 'Manager', 30 FROM dual)
SELECT ENAME
     , CASE WHEN position = MAX(position) over (ORDER BY ROWNUM 
                                                 ROWS BETWEEN 1 preceding AND 1 preceding) 
            THEN NULL 
            ELSE position 
       END position
     , deptno 
  FROM a 

如果值与上一行相同，则将在列NULL中显示POSITION。