CREATE PROCEDURE [dbo].[P_ExtensionLinkCount]
@BeginDate date
AS
BEGIN
    declare @Now date,
            @Yesterday date, -- 昨天
            @IsRefresh int   -- 是否更新某欄位 1更新 0不更新

    set @Now=GETDATE()
    set @Yesterday=DATEADD(day,-1,@Now)
    set @IsRefresh=0

    if @BeginDate = @Now or @BeginDate
 
 = @Yesterday
    begin
        set @IsRefresh=1
    end

    -- 更新指定日期（@BeginDate）資料
    ;with c1 as(
                -- 此處省略複雜邏輯
                select * from t1
        where State=1
    )
    MERGE INTO t2 as target
    USING c1 as source
    ON (target.id=source.id and target.date=source.date) 
    
 
WHEN MATCHED THEN  -- 存在則更新
        UPDATE  -- 如果是當天 則更新欄位 否則不更新某欄位
        SET target.c1= case when @IsRefresh=1 then source.c1 else target.c1 end,  
            target.c2= case when @IsRefresh=1 then source.c2 else target.c2 end,
            target.c3= source.c3,
            target.c4= source.c4,
            target.c5
 
= source.c5,
            target.c5= source.c6,
            target.c7= source.c7,
            target.c8=source.c8
    WHEN NOT MATCHED THEN -- 不存在則插入
        INSERT (c1,c2,c3,c4,c5,c6,c7,c8,c9,c10) 
        VALUES (c1,c2,c3,c4,c5,c6,c7,c8,c9,c10); 

END    

- 僅記錄sql結構與寫法，列名與表名已經抹掉；