Question

这是我的第一篇文章，我希望一切都会清楚。我有桌子，如：

client ; cost 
Paula  ; 100
Paula  ; 50
Jacob  ; 300
Paula  ; 120

我想添加另一个列“client2”，其中如果没有重复值，则值为1，或者如果有重复，则应该仅为具有最大成本的副本执行1，因此：

client ; cost ; client2
Paula  ; 100  ; 0
Paula  ; 50   ; 0
Jacob  ; 40   ; 1
Paula  ; 120  ; 1

在真实表格中有2000条记录。我应该如何在SQL Server中编写它？提前致谢，保

Answer 1

WITH CTE AS
    (SELECT
        client,
        cost,
        ROW_NUMBER() OVER (PARTITION BY client ORDER BY cost DESC) AS RowNo
    FROM
        table)
SELECT
    client,
    cost,
    CASE RowNo
        WHEN 1 THEN 1
        ELSE 0
    END AS client2
FROM
    CTE;

Answer 2

您可以使用cursor执行此操作。以下示例应该处理您想要的内容。您必须将#table替换为您的表名。像罪一样丑陋但它有效;）

 CREATE TABLE #Table
(
  client NVARCHAR(100),
  cost int,
  client1 int
);

INSERT INTO #Table
VALUES
('Paula',100,null),
('Paula',50,null),
('Jacob',300,null),
('Paula',120,null);

DECLARE @clientColumn nvarchar(100);
DECLARE @Dup int;

DECLARE client_cursor CURSOR FOR 
SELECT client,cost FROM #Table ORDER BY client,cost

OPEN client_cursor;
FETCH NEXT FROM client_cursor INTO @clientColumn

WHILE @@FETCH_STATUS=0
BEGIN

set @dup = (SELECT TOP 1 cost FROM #Table WHERE client = @clientColumn GROUP BY client ORDER BY cost desc )

UPDATE #Table
SET
    client1 = 1 
WHERE client = @clientColumn AND cost = @dup     

FETCH NEXT FROM client_cursor INTO @clientColumn
END
CLOSE client_cursor 
DEALLOCATE  client_cursor;

UPDATE #Table
SET
    client1 = 0
    WHERE client1 IS NULL

SELECT * FROM #Table

根据重复数据添加值

2 个答案: