Question

 DECLARE @fr varchar(50)
 DECLARE @to varchar(50)

 SELECT * 
 FROM test1.dbo.duplicate 
 WHERE dbavailability >= -1 

  IF (@fr='2014-05-01' AND @to='2014-05-04')
  BEGIN
    ALTER TABLE test1.dbo.duplicate ADD DEFAULT ((5)) FOR dbavailability
  END
Database data:

 id    | tpoi | date       | dbavailability
--------------------------------------------
 1     | A    | 2014-05-01 | 5
 1     | A    | 2014-05-02 | 4
 1     | A    | 2014-05-03 | 3
 1     | A    | 2014-05-04 | -1
Expected result:

 id    | tpoi | date       | dbavailability
--------------------------------------------
 1     | A    | 2014-05-01 | -1
 1     | A    | 2014-05-02 | -1
 1     | A    | 2014-05-03 | -1
 1     | A    | 2014-05-04 | -1

我在date列中有这个表数据，1到4 ok，dbavailability包含5,4,3，-1 ok现在我正在搜索记录，如从日期开始（2014-05-01）到目前为止（2014-05 -04）记录。在该记录中，dbavailability包含-1，那么对于特定id，整个列的dbavailability应为-1，因此如何将重复值添加到＆＃34; dbavailability＆＃34;柱？并且在我的查询中我使用if条件，但它没有得到正确的结果。

Answer 1

SELECT
 id, tpoi, "date", CASE WHEN id IN 
    (SELECT DISTINCT
            id 
        FROM 
            test1.dbo.duplicate 
        WHERE 
            dbavailability = -1) THEN '-1' ELSE dbavailability END AS dbAvailaility
FROM test1.dbo.duplicate 
WHERE 
date BETWEEN '2014-05-01' AND '2014-05-04'

如何在sql的现有列中添加重复值？

1 个答案: