如何将大量数据从一个表复制到SQL Server中的其他表

Question

我想将大量数据从一个表复制到另一个表.我在存储过程中使用游标来做同样的事情.但它只适用于记录较少的表.如果表包含更多记录,它会执行很长时间hanged.请给出一些建议,如何以更快的方式复制数据,我的SP如下:

--exec uds_shop

--select * from CMA_UDS.dbo.Dim_Shop
--select * from UDS.dbo.Dim_Shop
--delete from CMA_UDS.dbo.Dim_Shop

alter procedure uds_shop
as
begin
declare @dwkeyshop int
declare @shopdb int
declare @shopid int
declare @shopname nvarchar(60)
declare @shoptrade int
declare @dwkeytradecat int
declare @recordowner nvarchar(20)
declare @LogMessage varchar(600)

Exec CreateLog 'Starting Process', 1 

DECLARE cur_shop CURSOR FOR
    select 
    DW_Key_Shop,Shop_ID,Shop_Name,Trade_Sub_Category_Code,DW_Key_Source_DB,DW_Key_Trade_Category,Record_Owner
    from 
    UDS.dbo.Dim_Shop 

    OPEN  cur_shop
    FETCH NEXT FROM cur_shop INTO @dwkeyshop,@shopid,@shopname,@shoptrade, @shopdb ,@dwkeytradecat,@recordowner
    WHILE @@FETCH_STATUS = 0 
    BEGIN 
    Set @LogMessage = ''
    Set @LogMessage = 'Records insertion/updation start date and time : ''' + Convert(varchar(19), GetDate()) + ''''            

    if (isnull(@dwkeyshop, '') <> '')
        begin 
        if not exists (select crmshop.DW_Key_Shop from CMA_UDS.dbo.Dim_Shop as crmshop where (convert(varchar,crmshop.DW_Key_Shop)+CONVERT(varchar,crmshop.DW_Key_Source_DB)) = convert(varchar,(CONVERT(varchar, @dwkeyshop) + CONVERT(varchar, @shopdb))) )
        begin
        Set @LogMessage = Ltrim(Rtrim(@LogMessage)) + ' ' + 'Record for shop table is inserting...'         
                insert into 
                 CMA_UDS.dbo.Dim_Shop
                (DW_Key_Shop,DW_Key_Source_DB,DW_Key_Trade_Category,Record_Owner,Shop_ID,Shop_Name,Trade_Sub_Category_Code)
                values
                (@dwkeyshop,@shopdb,@dwkeytradecat,@recordowner,@shopid,@shopname,@shoptrade)
        Set @LogMessage = Ltrim(Rtrim(@LogMessage)) + ' ' + 'Record successfully inserted in shop table for shop Id : ' + Convert(varchar, @shopid) 

            end
            else

            begin 
             Set @LogMessage = Ltrim(Rtrim(@LogMessage)) + ' ' + 'Record for Shop table is updating...' 
             update 
             CMA_UDS.dbo.Dim_Shop
             set DW_Key_Trade_Category=@dwkeytradecat,
             Record_Owner=@recordowner,
             Shop_ID=@shopid,Shop_Name=@shopname,Trade_Sub_Category_Code=@shoptrade

             where       
                DW_Key_Shop=@dwkeyshop and DW_Key_Source_DB=@shopdb     
             Set @LogMessage = Ltrim(Rtrim(@LogMessage)) + ' ' + 'Record successfully updated for shop Id : ' + Convert(varchar, @shopid)
            end
        end
        Exec CreateLog @LogMessage, 0
        FETCH NEXT FROM cur_shop INTO @dwkeyshop,@shopid,@shopname,@shoptrade, @shopdb ,@dwkeytradecat,@recordowner
    end
    CLOSE cur_shop 
    DEALLOCATE cur_shop
End

Answer 1

假设targetTable并destinationTable拥有相同的架构......

INSERT INTO targetTable t
SELECT * FROM destinationTable d
WHERE someCriteria

除非没有其他方法(罕见),否则请避免使用游标.

您可以使用该WHERE子句筛选出任何重复记录.

如果您有标识列,请使用不包含标识列的显式列列表.

您可以尝试禁用约束并删除索引,前提是您替换它们(并确保检查约束).

如果您使用的是SQL Server 2008(之后),则可以使用该MERGE语句.