【发布时间】：2012-02-07 13:57:46
【问题描述】：
目前我在 SQL Server 检索过程中遇到问题。
当多个用户（用户数> 40）同时执行同一参数时，存储过程返回意外结果。对于 No of users
以下 SQL 语句应返回一行。但在重负载下，它有时不会返回任何行。
exec RetrievingNode @Keys='one,two,three'
这里是存储过程。
CREATE PROCEDURE [dbo].[RetrievingNode] @Keys nvarchar(max)
as
Begin
SET NOCOUNT ON;
--***************************************
--***************************************
-- Turn On or Off updation of LastAccessDateTime
-- To Turn on set @TurnOnUpdation=1
-- To Turn Off set @TurnOnUpdation=0
declare @TurnOnUpdation as bit
set @TurnOnUpdation=1
--***************************************
--***************************************
declare @Variable as table(
Value nvarchar(max),
KeyedNodes_Id int,
KeyNodeValue nvarchar(max),
IsParent bit,
IsReadOnly bit )
-- this table will hold ids against which LastAccessDateTime can be updated.
declare @tbl_Keys table(
id int identity(1, 1),
Value nvarchar(max))
--following will take all the keys into @tbl_Keys
insert into @tbl_Keys
(Value)
select Data
from Split(@Keys, ',')
DECLARE @count as int
DECLARE @counter as int
SET @counter=1
SELECT @count = COUNT(*)
FROM @tbl_Keys
--Declare @ChildId as int
declare @ChildNodes table(
id int,
Value nvarchar(max),
ParentNode_id int)
declare @ParentId as int
WHILE( @counter <= @count )
BEGIN
DECLARE @Key as nvarchar(max)
SELECT @Key = Value
FROM @tbl_Keys
WHERE id = @counter
if( @counter = 1 )
begin
if not exists(select *
from keyednodes(nolock) KN
where KN.Value = @Key
and KN.ParentNode_Id is null)
BEGIN
---node does not exists
Break;
END
declare @ValueExistsForFirstKey as bit
set @ValueExistsForFirstKey=0
insert into @ChildNodes
select k2.Id,
k2.Value,
k2.ParentNode_Id
from keyednodes(nolock) k1
inner join keyednodes(nolock) k2
on k1.id = k2.ParentNode_id
where K1.value = @Key
and k1.ParentNode_Id is null
if( @count = 1 )
BEGIN
IF EXISTS(select GV.Value,
GV.KeyedNodes_Id,
KN.Value
from keyednodes(nolock) KN
inner join GlobalVariables(nolock) GV
on KN.Id = GV.KeyedNodes_Id
and KN.Value = @Key
and KN.ParentNode_Id is null)
BEGIN -- If value of node exists
SET @ValueExistsForFirstKey=1
insert into @Variable
select GV.Value,
GV.KeyedNodes_Id,
KN.Value,
1,
GV.ReadOnly
from keyednodes(nolock) KN
inner join GlobalVariables(nolock) GV
on KN.Id = GV.KeyedNodes_Id
and KN.Value = @Key
and KN.ParentNode_Id is null
END
ELSE
IF NOT EXISTS(select *
from @ChildNodes)
BEGIN
insert into @Variable
select -1,
-1,
-1,
0,
0
--Node exists but No value or children exists
GOTO ExitFromProcedure
END
IF( @counter = @count )
BEGIN
if exists(select Id,
Value,
ParentNode_Id
from keyednodes(nolock) KN
where KN.Value = @Key
and KN.ParentNode_Id is null)
BEGIN
if( @ValueExistsForFirstKey = 0 )
and ( not exists(select *
from @ChildNodes) )
BEGIN
insert into @Variable
select -1,
-1,
-1,
0,
0
GOTO ExitFromProcedure
END
END
END
END
end
else
begin
declare @KeyIsChild as int
set @KeyIsChild=0
if exists(select *
from @ChildNodes
where Value = @Key)
begin
set @KeyIsChild=1
End
ELSE
BEGIN
--Key path does not exist
--print 'key path does not exist'
GOTO ExitFromProcedure
ENd
if not exists(select *
from @ChildNodes
where Value = @Key)
BEGIN
set @ParentId=0
END
ELSE
BEGIN
select @ParentId = Id
from @ChildNodes
where Value = @Key
ENd
delete @ChildNodes
if( @KeyIsChild = 1 )
begin
insert into @ChildNodes
select k2.Id,
k2.Value,
k2.ParentNode_Id
from keyednodes(nolock) k1
inner join keyednodes(nolock) k2
on k1.id = k2.ParentNode_id
where k2.ParentNode_Id = @ParentId
end
end
SET @counter=@counter + 1
END
if exists(select *
from @ChildNodes)
begin
IF EXISTS (select GV.Value,
CN.id,
CN.Value
from @ChildNodes CN
left outer join GlobalVariables(nolock) GV
on CN.Id = GV.KeyedNodes_Id --children
union all
select GV.Value,
GV.KeyedNodes_Id,
KN.Value
from keyednodes(nolock) KN
inner join GlobalVariables(nolock) GV
on KN.Id = GV.KeyedNodes_Id
and KN.Id = @ParentId--children
)
BEGIN
insert into @Variable
select GV.Value,
CN.id,
CN.Value,
0,
GV.ReadOnly
from @ChildNodes CN
left outer join GlobalVariables(nolock) GV
on CN.Id = GV.KeyedNodes_Id --children
union all
select GV.Value,
GV.KeyedNodes_Id,
KN.Value,
1,
GV.ReadOnly
from keyednodes(nolock) KN
inner join GlobalVariables(nolock) GV
on KN.Id = GV.KeyedNodes_Id
and KN.Id = @ParentId--children
END
ELSE
BEGIN
if( @count <> 1 )
insert into @Variable
select -1,
-1,
-1,
0,
0
if( @count = 1 )
and not exists(select *
from @Variable)
insert into @Variable
select -1,
-1,
-1,
0,
0
END
end
else
Begin
if ( @KeyIsChild = 1 )
BEGIN
IF EXISTS (select GV.Value,
GV.KeyedNodes_Id,
KN.Value
from keyednodes(nolock) KN
inner join GlobalVariables(nolock) GV
on KN.Id = GV.KeyedNodes_Id
and KN.Id = @ParentId)
BEGIN
---IF value of the node exists
insert into @Variable
select GV.Value,
GV.KeyedNodes_Id,
KN.Value,
1,
GV.ReadOnly
from keyednodes(nolock) KN
inner join GlobalVariables(nolock) GV
on KN.Id = GV.KeyedNodes_Id
and KN.Id = @ParentId --node
END
ELSE
BEGIN
insert into @Variable
select -1,
-1,
-1,
0,
0 --Node exists but No value or children exists
END
END
End
----
ExitFromProcedure:
select KeyedNodes_Id,
KeyNodeValue,
Value,
IsParent,
Isnull(IsReadOnly, 0)as IsReadOnly
from @Variable
order by IsParent desc,
KeyNodeValue asc
--update LastAccessDateTime
IF( @TurnOnUpdation = 1 )
BEGIN
IF EXISTS(select *
from @Variable)
BEGIN
UPDATE GlobalVariables
SET LastAccessDateTime = getdate()
WHERE KeyedNodes_Id IN (SELECT KeyedNodes_Id
FROM @Variable)
END
END
End
这是上述过程中引用的 Split() UDF：
CREATE FUNCTION [dbo].[Split] ( @RowData nvarchar(max), @SplitOn nvarchar(5) )
RETURNS @RtnValue table
(
Id int identity(1,1),
Data nvarchar(max)
) AS
BEGIN
Declare @Cnt int; Set @Cnt = 1
While (Charindex(@SplitOn,@RowData)>0)
Begin
Insert Into @RtnValue (data)
Select Data = ltrim(rtrim(Substring(@RowData,1,Charindex(@SplitOn,@RowData)-1)))
Set @RowData = Substring(@RowData,Charindex(@SplitOn,@RowData)+1,len(@RowData))
Set @Cnt = @Cnt + 1
End
Insert Into @RtnValue (data)
Select Data = ltrim(rtrim(@RowData))
Return
END
【问题讨论】：
-
在dba.stackexchange.com上问这个问题可能是个好主意
-
虽然左侧的“相关”边栏显示，SQL 开发问题，像这样的问题，在这里同样受到欢迎。跨度>
-
这看起来像SQL Server，你能告诉我们它是什么版本吗？
-
另外，您的“Split()”函数是一个自定义 UDF。你能把它的代码贴出来吗？
-
嗨，巴里，我无法发布我的 UDF 代码。可能是由于许多变量以@ chars 开头...你能帮我如何发布..this ..
标签： sql sql-server tsql sql-server-2008-r2