I may be wording this question very poorly but I am not 100% sure what I need to question.
I am trying to iterate over rows in a table and call a stored procedure using the data from the rows.
This is the code I already have, the problem with this is a timing issue (1000 rows takes around 1 minute);
--Set up a temp table with all non email alerts
SELECT TOP(1000)
RowNum = ROW_NUMBER() OVER(ORDER BY AlertID),
a.*, i.ImgData
INTO
#temp
FROM
dbo.ALERTS a
JOIN
dbo.IMAGES i ON i.VehicleID = a.VehicleID
WHERE
a.EmailImageSent = 0 OR a.EmailSent = 0
DECLARE #MaxRownum INT
SET #MaxRownum = (SELECT MAX(RowNum) FROM #temp)
DECLARE #Iter INT
SET #Iter = (SELECT MIN(RowNum) FROM #temp)
DECLARE #ImgData VARBINARY(MAX)
WHILE #Iter <= #MaxRownum
BEGIN
SELECT #VehicleID = VehicleID, #ImgData = ImgData
FROM #temp
WHERE RowNum = #Iter
IF #ImgData IS NOT NULL
BEGIN
EXEC dbo.someProcedure #VehicleID, #ImgData
--SELECT 'Image data found for', #VehicleID, #ImgData
END
SET #Iter = #Iter + 1
END
DROP TABLE #temp
Is there anyway I can run the stored procedure (dbo.someProcedure) while using a set based statement as the input?
Sorry if this has been asked before, I've had a look and couldn't find an answer or if this question isn't informative enough.
Thanks in advance
AFAIK sp_send_dbmail will need to be called once for each email, so either you have a loop here or you have a loop inside dbo.someProcedure.
Still I think that you could make some improvements. Use a FAST_FORWARD cursor rather than creating iteration variables and returning to the table each time to find the next row (thus creating 1000 table scans). Don't store redundant data in your #temp table, only what you need. This makes the table quicker to read.
Try this:
--Set up a temp table with all non email alerts
Create Table #temp (VehicleID int Primary Key Clustered, ImgData varbinary(max));
INSERT INTO #temp (VehicleID, ImgData)
SELECT TOP(1000)
a.VehicleID, i.ImgData
FROM
dbo.ALERTS a
JOIN
dbo.IMAGES i ON i.VehicleID = a.VehicleID
WHERE
a.EmailImageSent = 0 OR a.EmailSent = 0;
DECLARE #VehicleID int;
DECLARE #ImgData VARBINARY(MAX);
DECLARE Alert_Cursor Cursor Fast_Forward For (
Select VehicleID, ImgData From #temp);
OPEN Alert_Cursor;
FETCH NEXT FROM Alert_Cursor INTO #VehicleID, #ImgData;
WHILE ##FETCH_STATUS = 0
BEGIN
IF #ImgData IS NOT NULL
EXEC dbo.someProcedure #VehicleID, #ImgData;
FETCH NEXT FROM Alert_Cursor INTO #VehicleID, #ImgData;
END
CLOSE Alert_Cursor;
DEALLOCATE Alert_Cursor;
DROP TABLE #temp;
I have a table as follows
cat_id Cat_Name Main_Cat_Id
1 veg null
2 main course 1
3 starter 1
4 Indian 2
5 mexican 2
6 tahi 3
7 chinese 3
8 nonveg null
9 main course 8
10 indian 9
11 starter 8
12 tahi 11
13 chinese 11
(Main_Cat_Id is cat_id of previously added category in which it belongs)
This table is used for the categories the product where veg category has the two sub category main course and starter which is identify by main_cat_id
and those subcategories again has sub category as indian and mexican
And this categorization is dependent on the user; he can add more sub categories to indian, mexican also so that he can have any level of categorization
now I have to select all the subcategories of any node like if I take veg i have to select
(1)veg > (2)main course(1) > (4)indian(2)
> (5)mexican(2)
> (3)starter(1) > (6)thai(3)
> (7)chinese(3)
to form the string as 1,2,4,5,3,6,7
to do this i wrote a sql function as
CREATE FUNCTION [dbo].[GetSubCategory_TEST]
( #MainCategory int, #Category varchar(max))
RETURNS varchar(max)
AS
BEGIN
IF EXISTS (SELECT Cat_Id FROM Category WHERE Main_Cat_Id=#MainCategory)
BEGIN
DECLARE #TEMP TABLE
(
CAT_ID INT
)
INSERT INTO #TEMP(CAT_ID) SELECT Cat_Id FROM Category WHERE Main_Cat_Id=#MainCategory
DECLARE #TEMP_CAT_ID INT
DECLARE CUR_CAT_ID CURSOR FOR SELECT CAT_ID FROM #TEMP
OPEN CUR_CAT_ID
WHILE 1 =1
BEGIN
FETCH NEXT FROM CUR_CAT_ID
INTO #TEMP_CAT_ID;
IF ##FETCH_STATUS <> 0
SET #Category=#Category+','+ CONVERT(VARCHAR(50), #TEMP_CAT_ID)
SET #Category = [dbo].[GetSubCategory](#TEMP_CAT_ID,#Category)
END
CLOSE CUR_CAT_ID
DEALLOCATE CUR_CAT_ID
END
return #Category
END
but this function keep on executing and not gives the desired output i don't understands what wrong is going on plz help me to get this
You dont need a recursive function to build this, you can use a Recursive CTE for that.
Something like
DECLARE #TABLE TABLE(
cat_id INT,
Cat_Name VARCHAR(50),
Main_Cat_Id INT
)
INSERT INTO #TABLE SELECT 1,'veg',null
INSERT INTO #TABLE SELECT 2,'main course',1
INSERT INTO #TABLE SELECT 3,'starter',1
INSERT INTO #TABLE SELECT 4,'Indian',2
INSERT INTO #TABLE SELECT 5,'mexican',2
INSERT INTO #TABLE SELECT 6,'tahi',3
INSERT INTO #TABLE SELECT 7,'chinese',3
INSERT INTO #TABLE SELECT 8,'nonveg',null
INSERT INTO #TABLE SELECT 9,'main course',8
INSERT INTO #TABLE SELECT 10,'indian',9
INSERT INTO #TABLE SELECT 11,'starter',8
INSERT INTO #TABLE SELECT 12,'tahi',11
INSERT INTO #TABLE SELECT 13,'chinese',11
;WITH Recursives AS (
SELECT *,
CAST(cat_id AS VARCHAR(MAX)) + '\' ID_Path
FROM #TABLE
WHERE Main_Cat_Id IS NULL
UNION ALL
SELECT t.*,
r.ID_Path + CAST(t.cat_id AS VARCHAR(MAX)) + '\'
FROM #TABLE t INNER JOIN
Recursives r ON t.Main_Cat_Id = r.cat_id
)
SELECT *
FROM Recursives
I am ashamed, but I used #astander scipt to give string result.
First I created data you gave.
Second I collect rows which I need
And then using XML I put everything in one row (function STUFF removes first comma)
DECLARE #TABLE TABLE(
cat_id INT,
Cat_Name VARCHAR(50),
Main_Cat_Id INT
)
DECLARE #Collected TABLE(
cat_id INT
)
INSERT INTO #TABLE SELECT 1,'veg',null
INSERT INTO #TABLE SELECT 2,'main course',1
INSERT INTO #TABLE SELECT 3,'starter',1
INSERT INTO #TABLE SELECT 4,'Indian',2
INSERT INTO #TABLE SELECT 5,'mexican',2
INSERT INTO #TABLE SELECT 6,'tahi',3
INSERT INTO #TABLE SELECT 7,'chinese',3
INSERT INTO #TABLE SELECT 8,'nonveg',null
INSERT INTO #TABLE SELECT 9,'main course',8
INSERT INTO #TABLE SELECT 10,'indian',9
INSERT INTO #TABLE SELECT 11,'starter',8
INSERT INTO #TABLE SELECT 12,'tahi',11
INSERT INTO #TABLE SELECT 13,'chinese',11
INSERT INTO #TABLE SELECT 14,'chinese',6
DECLARE #nodeID INT = 1;
DECLARE #result VARCHAR(MAX);
;WITH Recursives AS (
SELECT cat_id, main_cat_id
FROM #TABLE
WHERE Cat_Id = #nodeID
UNION ALL
SELECT T.cat_id, T.main_cat_id
FROM #TABLE AS T
INNER JOIN Recursives AS R
ON t.Main_Cat_Id = r.cat_id
)
INSERT INTO #Collected
SELECT cat_id
FROM Recursives
SELECT #result = STUFF(
(SELECT ',' + CAST( cat_id AS VARCHAR)
FROM #Collected
ORDER BY cat_id
FOR XML PATH('')
), 1,1,'')
SELECT #result
Your cursor is looping infinitely because you asked it to keep going until 1 no longer equals 1:
WHILE 1 =1
1=1 is always true so the loop never ends, and you don't explicitly break out of it anywhere.
You would do well to study some examples of cursors, for example this one in the Microsoft T-SQL documentation. They are quite formulaic and the main syntax rarely needs to vary much.
The standard approach after opening the cursor is to do an initial fetch next to get the first result, then open a while loop conditional on ##FETCH_STATUS = 0 (0 meaning successful).
Because you're looking only for unsuccessful cursor fetch states inside your cursor:
IF ##FETCH_STATUS <> 0
The setting of #Category will only happen once the cursor has gone past the last row in the set. I suspect this is exactly what you don't want.
I'm also not sure about the scoping of the #Category variable, since it's an input parameter to the function; I generally create new variables inside a function to work with, but off the top of my head I'm not sure this will actually create a problem or not.
More generally, although I don't totally understand what you're trying to achieve here, a recursive function involving a cursor is probably not the right way to do it, as Adriaan Stander's answer suggests.
I have a table in which all entries are in form of arithmetic formulas (i.e. 1+2+3 etc).
In this table all columns are of type varchar. The table has many columns like this.
I want to calculate formula and insert the values into another. Any suggestions on how to achieve this?
You can try this. I hope this can assist you. It takes expression from t1 and put the result in t2. You won't want to make t1 the actual table as it deletes from the table, so you can copy the actual table value to a temp table
declare #t as table(val varchar(20))
declare #t2 as table(val varchar(20))
insert into #t values
('1+3'),
('2*3'),
('9+3*2')
declare #exp varchar(20)
while(exists(select 1 from #t))
begin
select top(1) #exp = val from #t
insert into #t2
exec ('select '+#exp)
delete top (1) from #t
end
select * from #t2
Result
val
------
4
6
15
You can check these links Similar question here and Convert string with expression to decimal
Follow the link -
Convert string with expression to decimal
After you create function DBO.EVAL , just Run :-
select dbo.eval(column_name) from table_name;
You can declare two table variables:
#tabformula in which will be stored the formulas
#tabresult in which will stored the results
There is an ID column that will be used for joining the two tables.
After filling the first table with the required formulas, you declare a cursor, and then you execute the formula and store the result into the #tabresult table.
declare #tabformula as table (id int identity(1,1), formula
varchar(200)) declare #tabresult as table (id int, result int)
insert into #tabformula(formula) values('1+4+6+7') ;
insert into #tabformula(formula) values('10+4+60+7');
insert into #tabformula(formula) values('1+4+6+70') ;
insert into #tabformula(formula) values('1+44+65+7');
declare c cursor for select ID,formula from #tabformula declare #id as
int declare #formula as varchar(200)
open c fetch c into #id,#formula while ##fetch_status=0 begin print
#formula insert into #tabresult (id,result) exec( 'select '+ #id +
','+#formula ) fetch c into #id,#formula end close c deallocate c
select T1.id,t1.formula,T2.result from #tabformula t1 inner join
#tabresult t2 on t1.id=t2.id
I've got a #TempTble which looks like this:
Col1,Col2,5,8,19,....
Also, I have another table with description that matches the keys in #TempTble:
key Descr
=== ====
5 Descr1
8 Descr2
19 Descr3
Which is the best way to loop through the #TempTble and rename its columns with the matching descriptions so it looks like this:
Col1,Col2,Descr1,Descr2,Descr3,...
Thanks in advance.
IF object_id('tempdb..#Temp') IS NOT NULL DROP TABLE #Temp
declare #map table ([key] sysname,Descr sysname)
INSERT INTO #map
select 5,'Descr1' UNION ALL
select 8,'Descr2' UNION ALL
select 19,'Descr3'
create table #Temp ([Col1] int,[Col2] int,[5] int,[8] int,[19] int)
DECLARE #name nvarchar(1035), #descr sysname;
DECLARE ColumnCursor CURSOR
LOCAL FORWARD_ONLY STATIC READ_ONLY TYPE_WARNING
FOR SELECT 'tempdb..#Temp.' + QUOTENAME(name), Descr
FROM tempdb.sys.columns
JOIN #map m ON m.[key]=name
where object_id=object_id('tempdb..#Temp');
OPEN ColumnCursor;
FETCH NEXT FROM ColumnCursor INTO #name, #descr;
WHILE ##FETCH_STATUS = 0
BEGIN;
EXECUTE tempdb..sp_rename #name, #descr,'COLUMN';
FETCH NEXT FROM ColumnCursor INTO #name, #descr;
END;
CLOSE ColumnCursor;
DEALLOCATE ColumnCursor;
SELECT * FROM #Temp
This is a bad design
One option is to run this code;copy the result and run it again
select 'exec tempdb..sp_rename ''#temp.['+t1.name+']'','''+t2.descrip+''''
from tempdb..syscolumns as t1 inner join mytable as t2 on t1.name=t2.[key]
where id=OBJECT_ID('tempdb..#temp') and t1.name like '[0-9]%'
Let's say I have the following simple table variable:
declare #databases table
(
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into #databases
Is declaring and using a cursor my only option if I wanted to iterate through the rows? Is there another way?
First of all you should be absolutely sure you need to iterate through each row — set based operations will perform faster in every case I can think of and will normally use simpler code.
Depending on your data it may be possible to loop using just SELECT statements as shown below:
Declare #Id int
While (Select Count(*) From ATable Where Processed = 0) > 0
Begin
Select Top 1 #Id = Id From ATable Where Processed = 0
--Do some processing here
Update ATable Set Processed = 1 Where Id = #Id
End
Another alternative is to use a temporary table:
Select *
Into #Temp
From ATable
Declare #Id int
While (Select Count(*) From #Temp) > 0
Begin
Select Top 1 #Id = Id From #Temp
--Do some processing here
Delete #Temp Where Id = #Id
End
The option you should choose really depends on the structure and volume of your data.
Note: If you are using SQL Server you would be better served using:
WHILE EXISTS(SELECT * FROM #Temp)
Using COUNT will have to touch every single row in the table, the EXISTS only needs to touch the first one (see Josef's answer below).
Just a quick note, if you are using SQL Server (2008 and above), the examples that have:
While (Select Count(*) From #Temp) > 0
Would be better served with
While EXISTS(SELECT * From #Temp)
The Count will have to touch every single row in the table, the EXISTS only needs to touch the first one.
This is how I do it:
declare #RowNum int, #CustId nchar(5), #Name1 nchar(25)
select #CustId=MAX(USERID) FROM UserIDs --start with the highest ID
Select #RowNum = Count(*) From UserIDs --get total number of records
WHILE #RowNum > 0 --loop until no more records
BEGIN
select #Name1 = username1 from UserIDs where USERID= #CustID --get other info from that row
print cast(#RowNum as char(12)) + ' ' + #CustId + ' ' + #Name1 --do whatever
select top 1 #CustId=USERID from UserIDs where USERID < #CustID order by USERID desc--get the next one
set #RowNum = #RowNum - 1 --decrease count
END
No Cursors, no temporary tables, no extra columns.
The USERID column must be a unique integer, as most Primary Keys are.
Define your temp table like this -
declare #databases table
(
RowID int not null identity(1,1) primary key,
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into #databases
Then do this -
declare #i int
select #i = min(RowID) from #databases
declare #max int
select #max = max(RowID) from #databases
while #i <= #max begin
select DatabaseID, Name, Server from #database where RowID = #i --do some stuff
set #i = #i + 1
end
Here is how I would do it:
Select Identity(int, 1,1) AS PK, DatabaseID
Into #T
From #databases
Declare #maxPK int;Select #maxPK = MAX(PK) From #T
Declare #pk int;Set #pk = 1
While #pk <= #maxPK
Begin
-- Get one record
Select DatabaseID, Name, Server
From #databases
Where DatabaseID = (Select DatabaseID From #T Where PK = #pk)
--Do some processing here
--
Select #pk = #pk + 1
End
[Edit] Because I probably skipped the word "variable" when I first time read the question, here is an updated response...
declare #databases table
(
PK int IDENTITY(1,1),
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into #databases
--/*
INSERT INTO #databases (DatabaseID, Name, Server) SELECT 1,'MainDB', 'MyServer'
INSERT INTO #databases (DatabaseID, Name, Server) SELECT 1,'MyDB', 'MyServer2'
--*/
Declare #maxPK int;Select #maxPK = MAX(PK) From #databases
Declare #pk int;Set #pk = 1
While #pk <= #maxPK
Begin
/* Get one record (you can read the values into some variables) */
Select DatabaseID, Name, Server
From #databases
Where PK = #pk
/* Do some processing here */
/* ... */
Select #pk = #pk + 1
End
If you have no choice than to go row by row creating a FAST_FORWARD cursor. It will be as fast as building up a while loop and much easier to maintain over the long haul.
FAST_FORWARD
Specifies a FORWARD_ONLY, READ_ONLY cursor with performance optimizations enabled. FAST_FORWARD cannot be specified if SCROLL or FOR_UPDATE is also specified.
This will work in SQL SERVER 2012 version.
declare #Rowcount int
select #Rowcount=count(*) from AddressTable;
while( #Rowcount>0)
begin
select #Rowcount=#Rowcount-1;
SELECT * FROM AddressTable order by AddressId desc OFFSET #Rowcount ROWS FETCH NEXT 1 ROWS ONLY;
end
Another approach without having to change your schema or using temp tables:
DECLARE #rowCount int = 0
,#currentRow int = 1
,#databaseID int
,#name varchar(15)
,#server varchar(15);
SELECT #rowCount = COUNT(*)
FROM #databases;
WHILE (#currentRow <= #rowCount)
BEGIN
SELECT TOP 1
#databaseID = rt.[DatabaseID]
,#name = rt.[Name]
,#server = rt.[Server]
FROM (
SELECT ROW_NUMBER() OVER (
ORDER BY t.[DatabaseID], t.[Name], t.[Server]
) AS [RowNumber]
,t.[DatabaseID]
,t.[Name]
,t.[Server]
FROM #databases t
) rt
WHERE rt.[RowNumber] = #currentRow;
EXEC [your_stored_procedure] #databaseID, #name, #server;
SET #currentRow = #currentRow + 1;
END
You can use a while loop:
While (Select Count(*) From #TempTable) > 0
Begin
Insert Into #Databases...
Delete From #TempTable Where x = x
End
Lightweight, without having to make extra tables, if you have an integer ID on the table
Declare #id int = 0, #anything nvarchar(max)
WHILE(1=1) BEGIN
Select Top 1 #anything=[Anything],#id=#id+1 FROM Table WHERE ID>#id
if(##ROWCOUNT=0) break;
--Process #anything
END
I really do not see the point why you would need to resort to using dreaded cursor.
But here is another option if you are using SQL Server version 2005/2008
Use Recursion
declare #databases table
(
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
--; Insert records into #databases...
--; Recurse through #databases
;with DBs as (
select * from #databases where DatabaseID = 1
union all
select A.* from #databases A
inner join DBs B on A.DatabaseID = B.DatabaseID + 1
)
select * from DBs
-- [PO_RollBackOnReject] 'FININV10532'
alter procedure PO_RollBackOnReject
#CaseID nvarchar(100)
AS
Begin
SELECT *
INTO #tmpTable
FROM PO_InvoiceItems where CaseID = #CaseID
Declare #Id int
Declare #PO_No int
Declare #Current_Balance Money
While (Select ROW_NUMBER() OVER(ORDER BY PO_LineNo DESC) From #tmpTable) > 0
Begin
Select Top 1 #Id = PO_LineNo, #Current_Balance = Current_Balance,
#PO_No = PO_No
From #Temp
update PO_Details
Set Current_Balance = Current_Balance + #Current_Balance,
Previous_App_Amount= Previous_App_Amount + #Current_Balance,
Is_Processed = 0
Where PO_LineNumber = #Id
AND PO_No = #PO_No
update PO_InvoiceItems
Set IsVisible = 0,
Is_Processed= 0
,Is_InProgress = 0 ,
Is_Active = 0
Where PO_LineNo = #Id
AND PO_No = #PO_No
End
End
It's possible to use a cursor to do this:
create function [dbo].f_teste_loop
returns #tabela table
(
cod int,
nome varchar(10)
)
as
begin
insert into #tabela values (1, 'verde');
insert into #tabela values (2, 'amarelo');
insert into #tabela values (3, 'azul');
insert into #tabela values (4, 'branco');
return;
end
create procedure [dbo].[sp_teste_loop]
as
begin
DECLARE #cod int, #nome varchar(10);
DECLARE curLoop CURSOR STATIC LOCAL
FOR
SELECT
cod
,nome
FROM
dbo.f_teste_loop();
OPEN curLoop;
FETCH NEXT FROM curLoop
INTO #cod, #nome;
WHILE (##FETCH_STATUS = 0)
BEGIN
PRINT #nome;
FETCH NEXT FROM curLoop
INTO #cod, #nome;
END
CLOSE curLoop;
DEALLOCATE curLoop;
end
I'm going to provide the set-based solution.
insert #databases (DatabaseID, Name, Server)
select DatabaseID, Name, Server
From ... (Use whatever query you would have used in the loop or cursor)
This is far faster than any looping techique and is easier to write and maintain.
I prefer using the Offset Fetch if you have a unique ID you can sort your table by:
DECLARE #TableVariable (ID int, Name varchar(50));
DECLARE #RecordCount int;
SELECT #RecordCount = COUNT(*) FROM #TableVariable;
WHILE #RecordCount > 0
BEGIN
SELECT ID, Name FROM #TableVariable ORDER BY ID OFFSET #RecordCount - 1 FETCH NEXT 1 ROW;
SET #RecordCount = #RecordCount - 1;
END
This way I don't need to add fields to the table or use a window function.
I agree with the previous post that set-based operations will typically perform better, but if you do need to iterate over the rows here's the approach I would take:
Add a new field to your table variable (Data Type Bit, default 0)
Insert your data
Select the Top 1 Row where fUsed = 0 (Note: fUsed is the name of the field in step 1)
Perform whatever processing you need to do
Update the record in your table variable by setting fUsed = 1 for the record
Select the next unused record from the table and repeat the process
DECLARE #databases TABLE
(
DatabaseID int,
Name varchar(15),
Server varchar(15),
fUsed BIT DEFAULT 0
)
-- insert a bunch rows into #databases
DECLARE #DBID INT
SELECT TOP 1 #DBID = DatabaseID from #databases where fUsed = 0
WHILE ##ROWCOUNT <> 0 and #DBID IS NOT NULL
BEGIN
-- Perform your processing here
--Update the record to "used"
UPDATE #databases SET fUsed = 1 WHERE DatabaseID = #DBID
--Get the next record
SELECT TOP 1 #DBID = DatabaseID from #databases where fUsed = 0
END
Step1: Below select statement creates a temp table with unique row number for each record.
select eno,ename,eaddress,mobno int,row_number() over(order by eno desc) as rno into #tmp_sri from emp
Step2:Declare required variables
DECLARE #ROWNUMBER INT
DECLARE #ename varchar(100)
Step3: Take total rows count from temp table
SELECT #ROWNUMBER = COUNT(*) FROM #tmp_sri
declare #rno int
Step4: Loop temp table based on unique row number create in temp
while #rownumber>0
begin
set #rno=#rownumber
select #ename=ename from #tmp_sri where rno=#rno **// You can take columns data from here as many as you want**
set #rownumber=#rownumber-1
print #ename **// instead of printing, you can write insert, update, delete statements**
end
This approach only requires one variable and does not delete any rows from #databases. I know there are a lot of answers here, but I don't see one that uses MIN to get your next ID like this.
DECLARE #databases TABLE
(
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into #databases
DECLARE #CurrID INT
SELECT #CurrID = MIN(DatabaseID)
FROM #databases
WHILE #CurrID IS NOT NULL
BEGIN
-- Do stuff for #CurrID
SELECT #CurrID = MIN(DatabaseID)
FROM #databases
WHERE DatabaseID > #CurrID
END
Here's my solution, which makes use of an infinite loop, the BREAK statement, and the ##ROWCOUNT function. No cursors or temporary table are necessary, and I only need to write one query to get the next row in the #databases table:
declare #databases table
(
DatabaseID int,
[Name] varchar(15),
[Server] varchar(15)
);
-- Populate the [#databases] table with test data.
insert into #databases (DatabaseID, [Name], [Server])
select X.DatabaseID, X.[Name], X.[Server]
from (values
(1, 'Roger', 'ServerA'),
(5, 'Suzy', 'ServerB'),
(8675309, 'Jenny', 'TommyTutone')
) X (DatabaseID, [Name], [Server])
-- Create an infinite loop & ensure that a break condition is reached in the loop code.
declare #databaseId int;
while (1=1)
begin
-- Get the next database ID.
select top(1) #databaseId = DatabaseId
from #databases
where DatabaseId > isnull(#databaseId, 0);
-- If no rows were found by the preceding SQL query, you're done; exit the WHILE loop.
if (##ROWCOUNT = 0) break;
-- Otherwise, do whatever you need to do with the current [#databases] table row here.
print 'Processing #databaseId #' + cast(#databaseId as varchar(50));
end
This is the code that I am using 2008 R2. This code that I am using is to build indexes on key fields (SSNO & EMPR_NO) n all tales
if object_ID('tempdb..#a')is not NULL drop table #a
select 'IF EXISTS (SELECT name FROM sysindexes WHERE name ='+CHAR(39)+''+'IDX_'+COLUMN_NAME+'_'+SUBSTRING(table_name,5,len(table_name)-3)+char(39)+')'
+' begin DROP INDEX [IDX_'+COLUMN_NAME+'_'+SUBSTRING(table_name,5,len(table_name)-3)+'] ON '+table_schema+'.'+table_name+' END Create index IDX_'+COLUMN_NAME+'_'+SUBSTRING(table_name,5,len(table_name)-3)+ ' on '+ table_schema+'.'+table_name+' ('+COLUMN_NAME+') ' 'Field'
,ROW_NUMBER() over (order by table_NAMe) as 'ROWNMBR'
into #a
from INFORMATION_SCHEMA.COLUMNS
where (COLUMN_NAME like '%_SSNO_%' or COLUMN_NAME like'%_EMPR_NO_')
and TABLE_SCHEMA='dbo'
declare #loopcntr int
declare #ROW int
declare #String nvarchar(1000)
set #loopcntr=(select count(*) from #a)
set #ROW=1
while (#ROW <= #loopcntr)
begin
select top 1 #String=a.Field
from #A a
where a.ROWNMBR = #ROW
execute sp_executesql #String
set #ROW = #ROW + 1
end
SELECT #pk = #pk + 1
would be better:
SET #pk += #pk
Avoid using SELECT if you are not referencing tables are are just assigning values.