【APT】SqlServer游标使用

use [ElephantCredit]
go
begin transaction tran_bank;
print '**脚本开始执行!';
declare @tran_error int ,
    @negRuleId uniqueidentifier
    set @tran_error = 0;
    set @negRuleId = (select Id from [ElephantCredit].[dbo].[CreditRules] where [Provider]=N'CREDIT_PROVIDER_OPS' and [Code]=N'OPS_DOCTOR_RULE_N7_N')
    begin
       declare cursor_credit cursor scroll for
            (select CreditId from [ElephantCredit].[dbo].[CreditHistories] where RuleId = @negRuleId
             group by CreditId
            )

        open cursor_credit;
        declare @CreditId uniqueidentifier,
                @FinalCredit int=0,
                @OldCredit int=0,
                @PeakCredit int=0
        fetch first from cursor_credit into @CreditId;
        while (@@fetch_status = 0)
        begin                   

                --0.calculate the final credits/ignore these negative rule records.
                set @FinalCredit = (select case when (sum(cast([value] as int)))<0 then 0 else sum(cast([value] as int)) end
                 from [ElephantCredit].[dbo].[CreditHistories] where CreditId=@CreditId and RuleId != @negRuleId)

                if (@FinalCredit is null)
                BEGIN
                   --break;
                   goto _out
                end 

                --1.update credits principal using the latest credit
                set @OldCredit = (select AvailableValue from [ElephantCredit].[dbo].[Credits] where Id=@CreditId)
                set @PeakCredit = (select PeakValue from [ElephantCredit].[dbo].[Credits] where Id=@CreditId) 

                update [ElephantCredit].[dbo].[Credits] set
                AvailableValue = @FinalCredit,
                UpdatedTime =GETDATE()
                where Id=@CreditId
                print '---creditId:'+ cast(@CreditId as nvarchar(50)) + ',重置成新积分值:'+ cast(@FinalCredit as varchar) +',旧值:' + cast(@OldCredit as varchar) + ',峰值:' + cast(@PeakCredit as varchar);

                --2.update groups principal
                update [ElephantCredit].[dbo].[Growths] set
                [Value] = @FinalCredit,
                UpdatedTime =GETDATE()
                where ExternalId=(select RefId from [ElephantCredit].[dbo].[Credits] where Id=@CreditId)
                print '---成长值同步更新完毕!' ;

                _out:
                fetch next from cursor_credit into @CreditId;  

        end
        close cursor_credit;
        deallocate cursor_credit;  

        --3.clear all the dirty data
        delete from [ElephantCredit].[dbo].[CreditHistories] where RuleId = @negRuleId
        print '清理全部脏数据完毕';
    end
if (@tran_error > 0)
    begin
        rollback tran;
        print '**脚本执行失败!已回滚';
    end
else
    begin
        commit tran;
        print '**脚本执行成功!';
    end
go

 --Helper:
 --select * from  CreditHistories
 --select * from Credits --where Id='9416FEBA-C19F-4718-80D5-F01643D57DE5'
 --select * from CreditRules