使用游标遍历 SQL 服务器中的 table 变量

Question

我有一个存储过程的参数，它以

格式获取一些数据

1/1/2018-2/1/2018,2/1/2018-3/1/2018,3/1/2018-4/1/2018,4/1/2018-5/1/2018,5/1/2018-6/1/2018,6/1/2018-7/1/2018,7/1/2018-8/1/2018,8/1/2018-9/1/2018,9/1/2018-10/1/2018,
10/1/2018-11/1/2018,11/1/2018-12/1/2018,12/1/2018-12/31/2018

我有一个函数可以根据 , 字符拆分数据并将结果存储到 table 变量中，如下所示：

declare @SPlitDates table(ItemNumber int, Item nvarchar(max))

insert into @SPlitDates
    select * 
    from dbo.SPlitFunction(@RequestData, ',')

在此之后我必须对数据范围执行某些操作所以我使用游标循环遍历临时 table 如下所示

DECLARE cur CURSOR FOR 
     SELECT Item 
     FROM @SPlitDates 
     ORDER BY ItemNumber

OPEN cur

FETCH NEXT FROM cur INTO @monthStart

WHILE @@FETCH_STATUS = 0 
BEGIN
     -- Some operation
END

我将在临时 table 中获得的最大数据点是 12 个月的日期范围。

我的问题是我是否可以使用游标以外的其他东西来提高性能，或者当数据集真的这么小时这并不重要。

谢谢

编辑 - 显示光标内的操作

declare @SPlitDates table(ItemNumber int, Item nvarchar(max))

insert into @SPlitDates
    select * 
    from dbo.SPlitFunction(@RequestData, ',')

declare @SPlitDatesData table (ItemNumber varchar(100), Item nvarchar(max))
declare @SPlitDatesAvgData table(Code nvarchar(100), Val decimal(18,2))
declare @dataFilter as nvarchar(max),
        @SQL as nvarchar(max);

declare @monthStart nvarchar(100)
declare @count int

set @count = 0

--Declaring a cursor to loop through all the dates as defined in the requested quarter
DECLARE cur CURSOR FOR 
     SELECT Item 
     FROM @SPlitDates 
     ORDER BY ItemNumber

OPEN cur

FETCH NEXT FROM cur INTO @monthStart

WHILE @@FETCH_STATUS = 0 
BEGIN
    DECLARE @Period NVARCHAR(100)
    SET @Period = @monthStart

    INSERT INTO @SPlitDatesData
        --split the dates to get the start and the end dates
        SELECT * 
        FROM dbo.SPlitFunction(@Period, '-')

    DECLARE @PeriodStart NVARCHAR(100)
    DECLARE @PeriodEnd NVARCHAR(100)

    SET @PeriodStart = (SELECT Item FROM @SPlitDatesData WHERE ItemNumber = 1)
    SET @PeriodEnd = (SELECT Item FROM @SPlitDatesData WHERE ItemNumber = 2)

    DELETE FROM @SPlitDatesData

    --add the start and end dates to the filter
    SET @dataFilter = 'StatusDate between convert(datetime,('''+@PeriodStart+'''))  
    and DATEADD(dy, 1, convert(datetime,('''+@PeriodEnd+''')))'

    SET @count = @count +1;
    SET @SQL = 'INSERT INTO #BidAverageCycleCalculation (SortOrder, Code, Data)
                VALUES (@count,
    ''SL Payroll'',(select dbo.GetAverageCycleBetweenBids('''+@PeriodStart+''',
    '''+@PeriodEnd+''',''SL''))
     )'

    EXEC SP_ExecuteSQL @SQL, N'@count int', @count;

    SET @count = @count +1;
    SET @SQL = 'INSERT INTO #BidAverageCycleCalculation (SortOrder, Code, Data)
                VALUES (@count,
    ''GV Payroll'',(select dbo.GetAverageCycleBetweenBids('''+@PeriodStart+''',
    '''+@PeriodEnd+''',''GV''))
     )'

    EXEC SP_ExecuteSQL @SQL , N'@count int', @count;

    SET @count = @count +1;

    SET @SQL = 'Insert into #BidAverageCycleCalculation (SortOrder,Code,Data)
  Values (@count,
    ''Global Payroll'',(select dbo.GetAverageCycleBetweenBids('''+@PeriodStart+''',
    '''+@PeriodEnd+''',''GVS''))
     )'

    EXEC SP_ExecuteSQL @SQL, N'@count int', @count;

    SET @count = @count +1;

    SET @SQL = 'Insert into #BidAverageCycleCalculation (SortOrder,Code,Data)
  Values (@count,
    ''TimeHCM'',(select dbo.GetAverageCycleBetweenBids('''+@PeriodStart+''',
    '''+@PeriodEnd+''',''Time''))
     )' 

    EXEC SP_ExecuteSQL @SQL, N'@count int', @count;    

    delete from @SPlitDatesAVgData  

    FETCH NEXT FROM cur INTO @monthStart
END

CLOSE cur    
DEALLOCATE cur

Answer 1

这使用两个部分 - 首先将您的字符串转换为 table，然后将批量插入到您的目标中。不需要游标。

** 请原谅任何语法错误，因为我在执行此操作时无法访问您的实际 tables 或函数，因此无法对其进行测试，但您明白了

declare @in varchar(max)
set @in= '1/1/2018-2/1/2018,2/1/2018-3/1/2018,3/1/2018-4/1/2018,4/1/2018-5/1/2018,5/1/2018-6/1/2018,6/1/2018-7/1/2018,7/1/2018-8/1/2018,8/1/2018-9/1/2018,9/1/2018-10/1/2018,10/1/2018-11/1/2018,11/1/2018-12/1/2018,12/1/2018-12/31/2018'

declare @xml xml;
set @xml= convert(xml,'<r><f>'+replace(replace(@in,',','</t></r><r><f>'),'-','</f><t>') +'</t></r>')

declare @t table(id int identity, f date, t date)
insert @t
select 
    Tbl.Col.value('f[1]', 'date') f, 
    Tbl.Col.value('t[1]', 'date') t
FROM  @xml.nodes('//r') Tbl(Col) 

select * from @t

declare @count int;
select @count=count(*) from @t

INSERT INTO #BidAverageCycleCalculation (SortOrder, Code, Data)
select id, 'SL Payroll',(select dbo.GetAverageCycleBetweenBids(f,t,'SL')) from @t

INSERT INTO #BidAverageCycleCalculation (SortOrder, Code, Data)
select id+@count,'GV Payroll',(select dbo.GetAverageCycleBetweenBids(f,t,'GV')) from @t

INSERT INTO #BidAverageCycleCalculation (SortOrder, Code, Data)
select id+@count*2,'Global Payroll',(select dbo.GetAverageCycleBetweenBids(f,t,'GVS')) from @t

INSERT INTO #BidAverageCycleCalculation (SortOrder, Code, Data)
select id+@count*3,'TimeHCM',(select dbo.GetAverageCycleBetweenBids(f,t,'Time')) from @t

使用游标遍历 SQL 服务器中的 table 变量

Using cursor to loop through a table variable in SQL Server

sql

sql-server

sql-server-2008