Question

我有一个带有20,000个条目的表。

我需要复制“某些”数据，但是要使用新的公司名称。

该表具有一个不会自动递增的唯一ID，因此在每次插入过程中，我需要找到MAX（UniqueID）并添加1。

以下脚本有效，但是性能很差。

DECLARE @RowCount AS INTEGER;
SELECT  @RowCount = COUNT(1)
FROM    [dbo].[TableAAA];


DECLARE @intFlag INT;
SET @intFlag = 1;
WHILE ( @intFlag <= @RowCount )
    BEGIN
        INSERT  INTO [dbo].[TableAAA]
                ( UniqueID ,
                  company ,
                  Agent ,
                  Phone
                )
                SELECT TOP 1
                        ( SELECT    MAX(UniqueID) + 1
                          FROM      [dbo].[TableAAA]
                        ) ,
                        'New Company' ,
                        Agent ,
                        Phone
                FROM    [dbo].[TableAAA] c
                WHERE   c.companyid = 'Old Company'
                        AND c.phone NOT IN ( SELECT Phone
                                             FROM   [dbo].[TableAAA]
                                             WHERE  company = 'New Company' );


        SET @intFlag = @intFlag + 1;
    END;

Answer 1

我会使用MAX（UniqueID）作为SEED，然后以基于集合的方法将其递增

declare @Seed int = (select MAX(UniqueID) FROM [dbo].[TableAAA])

SELECT 
   ID = row_number() over (order by (select null)) + @Seed
   'New Company',
    Agent,
    Phone
INTO 
    #Staging
FROM
    [dbo].[TableAAA] c
WHERE   
    c.companyid = 'Old Company'
    AND c.phone NOT IN ( SELECT Phone
                         FROM   [dbo].[TableAAA]
                         WHERE  company = 'New Company' )

INSERT INTO  [dbo].[TableAAA]
              (UniqueID,
               company,
               Agent,
               Phone)
SELECT
    ID,
    [New Company],
    Agent,
    Phone
FROM #Staging

DROP TABLE #Staging

同一SQL表中的部分重复数据

1 个答案: