TSQL: Using a Table in a Variable in a Function - sql

I'm trying to do a select from a table that will need to be in a variable. I'm working with tables that are dynamically created from an application. The table will be named CMDB_CI_XXX, where XXX will be an integer value based on a value in another table. The ultimate goal is to get the CI Name from the table.
I've tried passing the pieces that make up the table name to a function and string them together and then return the name value, but I'm not allowed to use an EXEC statement in a function.
This is what I want to execute to get the name value back:
Select [Name] from 'CMDB_CI_' + C.CI_TYPE_ID + Where CI_ID = c.CI_ID
This is the code in the SP that I'd like to use the function in to get the name value:
SELECT
CI_ID,
C.CI_TYPE_ID,
CI_CUSTOM_ID,
STATUS,
CI_TYPE_NAME,
--(Select [Name] from CMDB_CI_ + C.CI_TYPE_ID + Where CI_ID = c.CI_ID)
FROM [footprints].[dbo].[CMDB50_CI_COMMON] c
join [footprints].[dbo].[CMDB50_CI_TYPE] t
on c.CI_TYPE_ID = t.CI_TYPE_ID
where status <> 'retired'
order by CI_TYPE_NAME
I'm not sure what to do with this. Please help?
Thanks,
Jennifer

-- This part would be a SP parameter I expect
DECLARE #tableName varchar(100)
SET #tableName = 'CMDB_CI_508'
-- Main SP code
DECLARE #sqlStm VARCHAR(MAX)
SET #sqlStm = 'SELECT *
FROM '+ #tableName
EXEC (#sqlStm)
Fiddle http://sqlfiddle.com/#!3/436a7/7

First off, yes, I know it's a bad design. I didn't design it. It came with the problem tracking software that my company bought for our call center. So I gave up altogether on the approach I was going for and used a cursor to pull all the the names from the various tables into one temp table and then used said temp table to join to the original query.
ALTER Proc [dbo].[CI_CurrentItems]
As
Declare #CIType nvarchar(6)
Declare #Qry nvarchar(100)
/*
Create Table Temp_CI
( T_CI_ID int,
T_CI_Type_ID int,
T_Name nvarchar(400)
)
*/
Truncate Table Temp_CI
Declare CI_Cursor Cursor For
select distinct CI_TYPE_ID FROM [footprints].[dbo].[CMDB50_CI_COMMON]
where STATUS <> 'Retired'
Open CI_Cursor
Fetch Next from CI_Cursor into #CIType
While ##FETCH_STATUS = 0
BEGIN
Set #Qry = 'Select CI_ID, CI_Type_ID, Name from Footprints.dbo.CMDB50_CI_' + #CIType
Insert into Temp_CI Exec (#Qry)
Fetch Next from CI_Cursor into #CIType
END
Close CI_Cursor
Deallocate CI_Cursor
SELECT CI_ID,
C.CI_TYPE_ID,
CI_CUSTOM_ID,
STATUS,
CI_TYPE_NAME,
T_Name
FROM [footprints].[dbo].[CMDB50_CI_COMMON] c
JOIN [footprints].[dbo].[CMDB50_CI_TYPE] t
ON c.CI_TYPE_ID = t.CI_TYPE_ID
JOIN Temp_CI tc
ON c.CI_ID = tc.T_CI_ID
AND t.CI_TYPE_ID = tc.T_CI_TYPE_ID
WHERE STATUS <> 'retired'
ORDER BY CI_TYPE_NAME

Related

SQL script for updating SQL Extended Properties with a Cursor

I have a task of updating the tables in a database which are missing Extended Properties for 'Category' and 'Description'. The script below is what I am currently trying to implement, but it doesn't function as I'd hoped it would.
The first part of the script successfully returns the tables which have NULL or missing values for 'Category' and 'Description'. These results are used by a cursor to iterate through each table so I can perform an operation on them. For each table in the cursor, I want to retrieve the correct values from TemporaryTable which contains the correct 'Category' and 'Description'. Then, pass those correct values to the EXEC statements to update or create the Extended Property. The only thing that doesn't seem to work is that the variables 'categ' and 'descr' don't get assigned the values in the second SELECT statement where I expected them to.
I've tried as many combinations as I can think of to get these values into the variables, but none seem to work for me. Hopefully somebody can point out where I am going wrong.
Thanks in advance for your suggestions.
Few variables declared for use in this script
*/
DECLARE #tablename VARCHAR(100)
DECLARE #categ VARCHAR(50)
DECLARE #descr VARCHAR(MAX)
DECLARE myCursor CURSOR FOR
/*
This SELECT/FROM returns all table names which have
a NULL value for either category or description. This statement correctly
returns the subset of tables.
*/
SELECT
t.name AS tablename
FROM sys.tables t
LEFT JOIN sys.extended_properties AS description
ON t.object_id = description.major_id
AND description.minor_id = 0
AND description.name = 'MS_Description'
LEFT JOIN sys.extended_properties AS category
ON t.object_id = category.major_id
AND category.minor_id = 0
AND category.name = 'Table_Category'
WHERE type = 'U'
AND (category.value IS NULL OR description.value IS NULL)
AND t.name NOT LIKE 'temp%'
AND t.name NOT LIKE 'tmp%'
AND t.name NOT LIKE '%_BAK'
OPEN myCursor
FETCH NEXT FROM myCursor INTO #tablename
WHILE ##FETCH_STATUS = 0
BEGIN
/*
This SELECT/FROM/WHERE takes information (correct extended properties) about all
cursor tables from a temporary table.
The purpose is to update the NULL (or not present) extended properties in the subset of tables
of the cursor.
The [Table Name], tp.Category, and tp.Description are correctly output in the results, but the assignment
to the variables categ, and descr (which I want to use in the EXEC statement for updating properties)
doesn't seem to happen.
*/
SELECT
tp.[Table Name],
tp.Category AS categ,
tp.Description AS descr
FROM TemporaryTable tp
WHERE #tablename = tp.[Table Name]
--If category ext_prop doesn't exist, add it
IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES WHERE [major_id] = OBJECT_ID(#tablename) AND [name] = N'Table_Category' AND [minor_id] = 0)
EXEC sys.sp_addextendedproperty #name=N'Table_Category', #value=N#categ , #level0type=N'SCHEMA',#level0name=N'dbo', #level1type=N'TABLE',#level1name=N#tablename
--Else, update extended property
ELSE
EXEC sys.sp_updateextendedproperty #name=N'Table_Category', #value=N#categ , #level0type=N'SCHEMA',#level0name=N'dbo', #level1type=N'TABLE',#level1name=N#tablename
--If description ext_prop doesn't exist, add extended property
IF NOT EXISTS (SELECT NULL FROM SYS.EXTENDED_PROPERTIES WHERE [major_id] = OBJECT_ID(#tablename) AND [name] = N'MS_Description' AND [minor_id] = 0)
EXEC sys.sp_updateextendedproperty #name=N'MS_Description', #value=N#desc , #level0type=N'SCHEMA',#level0name=N'dbo', #level1type=N'TABLE',#level1name=N#tablename
--If Not Exists, add extended property
ELSE
EXEC sys.sp_addextendedproperty #name=N'MS_Description', #value=N#desc , #level0type=N'SCHEMA',#level0name=N'dbo', #level1type=N'TABLE',#level1name=N#tablename
PRINT #categ
FETCH NEXT FROM myCursor INTO #tablename
END
CLOSE myCursor
DEALLOCATE myCursor
I don't see any trace of variable assignments, just aliases.
To assign a value to a variable you must either use
SET #varname = value or query
or you can do it using a select statement like
SELECT
#categ = tp.Category,
#descr = tp.Description
FROM TemporaryTable tp
WHERE #tablename = tp.[Table Name]

Using a temp table with a stored procedure to cycle through IDs [duplicate]

How can one call a stored procedure for each row in a table, where the columns of a row are input parameters to the sp without using a Cursor?
Generally speaking I always look for a set based approach (sometimes at the expense of changing the schema).
However, this snippet does have its place..
-- Declare & init (2008 syntax)
DECLARE #CustomerID INT = 0
-- Iterate over all customers
WHILE (1 = 1)
BEGIN
-- Get next customerId
SELECT TOP 1 #CustomerID = CustomerID
FROM Sales.Customer
WHERE CustomerID > #CustomerId
ORDER BY CustomerID
-- Exit loop if no more customers
IF ##ROWCOUNT = 0 BREAK;
-- call your sproc
EXEC dbo.YOURSPROC #CustomerId
END
You could do something like this: order your table by e.g. CustomerID (using the AdventureWorks Sales.Customer sample table), and iterate over those customers using a WHILE loop:
-- define the last customer ID handled
DECLARE #LastCustomerID INT
SET #LastCustomerID = 0
-- define the customer ID to be handled now
DECLARE #CustomerIDToHandle INT
-- select the next customer to handle
SELECT TOP 1 #CustomerIDToHandle = CustomerID
FROM Sales.Customer
WHERE CustomerID > #LastCustomerID
ORDER BY CustomerID
-- as long as we have customers......
WHILE #CustomerIDToHandle IS NOT NULL
BEGIN
-- call your sproc
-- set the last customer handled to the one we just handled
SET #LastCustomerID = #CustomerIDToHandle
SET #CustomerIDToHandle = NULL
-- select the next customer to handle
SELECT TOP 1 #CustomerIDToHandle = CustomerID
FROM Sales.Customer
WHERE CustomerID > #LastCustomerID
ORDER BY CustomerID
END
That should work with any table as long as you can define some kind of an ORDER BY on some column.
DECLARE #SQL varchar(max)=''
-- MyTable has fields fld1 & fld2
Select #SQL = #SQL + 'exec myproc ' + convert(varchar(10),fld1) + ','
+ convert(varchar(10),fld2) + ';'
From MyTable
EXEC (#SQL)
Ok, so I would never put such code into production, but it does satisfy your requirements.
I'd use the accepted answer, but another possibility is to use a table variable to hold a numbered set of values (in this case just the ID field of a table) and loop through those by Row Number with a JOIN to the table to retrieve whatever you need for the action within the loop.
DECLARE #RowCnt int; SET #RowCnt = 0 -- Loop Counter
-- Use a table variable to hold numbered rows containg MyTable's ID values
DECLARE #tblLoop TABLE (RowNum int IDENTITY (1, 1) Primary key NOT NULL,
ID INT )
INSERT INTO #tblLoop (ID) SELECT ID FROM MyTable
-- Vars to use within the loop
DECLARE #Code NVarChar(10); DECLARE #Name NVarChar(100);
WHILE #RowCnt < (SELECT COUNT(RowNum) FROM #tblLoop)
BEGIN
SET #RowCnt = #RowCnt + 1
-- Do what you want here with the data stored in tblLoop for the given RowNum
SELECT #Code=Code, #Name=LongName
FROM MyTable INNER JOIN #tblLoop tL on MyTable.ID=tL.ID
WHERE tl.RowNum=#RowCnt
PRINT Convert(NVarChar(10),#RowCnt) +' '+ #Code +' '+ #Name
END
Marc's answer is good (I'd comment on it if I could work out how to!)
Just thought I'd point out that it may be better to change the loop so the SELECT only exists once (in a real case where I needed to do this, the SELECT was quite complex, and writing it twice was a risky maintenance issue).
-- define the last customer ID handled
DECLARE #LastCustomerID INT
SET #LastCustomerID = 0
-- define the customer ID to be handled now
DECLARE #CustomerIDToHandle INT
SET #CustomerIDToHandle = 1
-- as long as we have customers......
WHILE #LastCustomerID <> #CustomerIDToHandle
BEGIN
SET #LastCustomerId = #CustomerIDToHandle
-- select the next customer to handle
SELECT TOP 1 #CustomerIDToHandle = CustomerID
FROM Sales.Customer
WHERE CustomerID > #LastCustomerId
ORDER BY CustomerID
IF #CustomerIDToHandle <> #LastCustomerID
BEGIN
-- call your sproc
END
END
If you can turn the stored procedure into a function that returns a table, then you can use cross-apply.
For example, say you have a table of customers, and you want to compute the sum of their orders, you would create a function that took a CustomerID and returned the sum.
And you could do this:
SELECT CustomerID, CustomerSum.Total
FROM Customers
CROSS APPLY ufn_ComputeCustomerTotal(Customers.CustomerID) AS CustomerSum
Where the function would look like:
CREATE FUNCTION ComputeCustomerTotal
(
#CustomerID INT
)
RETURNS TABLE
AS
RETURN
(
SELECT SUM(CustomerOrder.Amount) AS Total FROM CustomerOrder WHERE CustomerID = #CustomerID
)
Obviously, the example above could be done without a user defined function in a single query.
The drawback is that functions are very limited - many of the features of a stored procedure are not available in a user-defined function, and converting a stored procedure to a function does not always work.
For SQL Server 2005 onwards, you can do this with CROSS APPLY and a table-valued function.
Using CROSS APPLY in SQL Server 2005
Just for clarity, I'm referring to those cases where the stored procedure can be converted into a table valued function.
This is a variation on the answers already provided, but should be better performing because it doesn't require ORDER BY, COUNT or MIN/MAX. The only disadvantage with this approach is that you have to create a temp table to hold all the Ids (the assumption is that you have gaps in your list of CustomerIDs).
That said, I agree with #Mark Powell though that, generally speaking, a set based approach should still be better.
DECLARE #tmp table (Id INT IDENTITY(1,1) PRIMARY KEY NOT NULL, CustomerID INT NOT NULL)
DECLARE #CustomerId INT
DECLARE #Id INT = 0
INSERT INTO #tmp SELECT CustomerId FROM Sales.Customer
WHILE (1=1)
BEGIN
SELECT #CustomerId = CustomerId, #Id = Id
FROM #tmp
WHERE Id = #Id + 1
IF ##rowcount = 0 BREAK;
-- call your sproc
EXEC dbo.YOURSPROC #CustomerId;
END
This is a variation of n3rds solution above. No sorting by using ORDER BY is needed, as MIN() is used.
Remember that CustomerID (or whatever other numerical column you use for progress) must have a unique constraint. Furthermore, to make it as fast as possible CustomerID must be indexed on.
-- Declare & init
DECLARE #CustomerID INT = (SELECT MIN(CustomerID) FROM Sales.Customer); -- First ID
DECLARE #Data1 VARCHAR(200);
DECLARE #Data2 VARCHAR(200);
-- Iterate over all customers
WHILE #CustomerID IS NOT NULL
BEGIN
-- Get data based on ID
SELECT #Data1 = Data1, #Data2 = Data2
FROM Sales.Customer
WHERE [ID] = #CustomerID ;
-- call your sproc
EXEC dbo.YOURSPROC #Data1, #Data2
-- Get next customerId
SELECT #CustomerID = MIN(CustomerID)
FROM Sales.Customer
WHERE CustomerID > #CustomerId
END
I use this approach on some varchars I need to look over, by putting them in a temporary table first, to give them an ID.
If you don't what to use a cursor I think you'll have to do it externally (get the table, and then run for each statement and each time call the sp)
it Is the same as using a cursor, but only outside SQL.
Why won't you use a cursor ?
I usually do it this way when it's a quite a few rows:
Select all sproc parameters in a dataset with SQL Management Studio
Right-click -> Copy
Paste in to excel
Create single-row sql statements with a formula like '="EXEC schema.mysproc #param=" & A2' in a new excel column. (Where A2 is your excel column containing the parameter)
Copy the list of excel statements into a new query in SQL Management Studio and execute.
Done.
(On larger datasets i'd use one of the solutions mentioned above though).
DELIMITER //
CREATE PROCEDURE setFakeUsers (OUT output VARCHAR(100))
BEGIN
-- define the last customer ID handled
DECLARE LastGameID INT;
DECLARE CurrentGameID INT;
DECLARE userID INT;
SET #LastGameID = 0;
-- define the customer ID to be handled now
SET #userID = 0;
-- select the next game to handle
SELECT #CurrentGameID = id
FROM online_games
WHERE id > LastGameID
ORDER BY id LIMIT 0,1;
-- as long as we have customers......
WHILE (#CurrentGameID IS NOT NULL)
DO
-- call your sproc
-- set the last customer handled to the one we just handled
SET #LastGameID = #CurrentGameID;
SET #CurrentGameID = NULL;
-- select the random bot
SELECT #userID = userID
FROM users
WHERE FIND_IN_SET('bot',baseInfo)
ORDER BY RAND() LIMIT 0,1;
-- update the game
UPDATE online_games SET userID = #userID WHERE id = #CurrentGameID;
-- select the next game to handle
SELECT #CurrentGameID = id
FROM online_games
WHERE id > LastGameID
ORDER BY id LIMIT 0,1;
END WHILE;
SET output = "done";
END;//
CALL setFakeUsers(#status);
SELECT #status;
A better solution for this is to
Copy/past code of Stored Procedure
Join that code with the table for which you want to run it again (for each row)
This was you get a clean table-formatted output. While if you run SP for every row, you get a separate query result for each iteration which is ugly.
In case the order is important
--declare counter
DECLARE #CurrentRowNum BIGINT = 0;
--Iterate over all rows in [DataTable]
WHILE (1 = 1)
BEGIN
--Get next row by number of row
SELECT TOP 1 #CurrentRowNum = extendedData.RowNum
--here also you can store another values
--for following usage
--#MyVariable = extendedData.Value
FROM (
SELECT
data.*
,ROW_NUMBER() OVER(ORDER BY (SELECT 0)) RowNum
FROM [DataTable] data
) extendedData
WHERE extendedData.RowNum > #CurrentRowNum
ORDER BY extendedData.RowNum
--Exit loop if no more rows
IF ##ROWCOUNT = 0 BREAK;
--call your sproc
--EXEC dbo.YOURSPROC #MyVariable
END
I had some production code that could only handle 20 employees at a time, below is the framework for the code. I just copied the production code and removed stuff below.
ALTER procedure GetEmployees
#ClientId varchar(50)
as
begin
declare #EEList table (employeeId varchar(50));
declare #EE20 table (employeeId varchar(50));
insert into #EEList select employeeId from Employee where (ClientId = #ClientId);
-- Do 20 at a time
while (select count(*) from #EEList) > 0
BEGIN
insert into #EE20 select top 20 employeeId from #EEList;
-- Call sp here
delete #EEList where employeeId in (select employeeId from #EE20)
delete #EE20;
END;
RETURN
end
I had a situation where I needed to perform a series of operations on a result set (table). The operations are all set operations, so its not an issue, but...
I needed to do this in multiple places. So putting the relevant pieces in a table type, then populating a table variable w/ each result set allows me to call the sp and repeat the operations each time i need to .
While this does not address the exact question he asks, it does address how to perform an operation on all rows of a table without using a cursor.
#Johannes offers no insight into his motivation , so this may or may not help him.
my research led me to this well written article which served as a basis for my solution
https://codingsight.com/passing-data-table-as-parameter-to-stored-procedures/
Here is the setup
drop type if exists cpRootMapType
go
create type cpRootMapType as Table(
RootId1 int
, RootId2 int
)
go
drop procedure if exists spMapRoot2toRoot1
go
create procedure spMapRoot2toRoot1
(
#map cpRootMapType Readonly
)
as
update linkTable set root = root1
from linktable lt
join #map m on lt.root = root2
update comments set root = root1
from comments c
join #map m on c.root = root2
-- ever growing list of places this map would need to be applied....
-- now consolidated into one place
here is the implementation
... populate #matches
declare #map cpRootMapType
insert #map select rootid1, rootid2 from #matches
exec spMapRoot2toRoot1 #map
I like to do something similar to this (though it is still very similar to using a cursor)
[code]
-- Table variable to hold list of things that need looping
DECLARE #holdStuff TABLE (
id INT IDENTITY(1,1) ,
isIterated BIT DEFAULT 0 ,
someInt INT ,
someBool BIT ,
otherStuff VARCHAR(200)
)
-- Populate your #holdStuff with... stuff
INSERT INTO #holdStuff (
someInt ,
someBool ,
otherStuff
)
SELECT
1 , -- someInt - int
1 , -- someBool - bit
'I like turtles' -- otherStuff - varchar(200)
UNION ALL
SELECT
42 , -- someInt - int
0 , -- someBool - bit
'something profound' -- otherStuff - varchar(200)
-- Loop tracking variables
DECLARE #tableCount INT
SET #tableCount = (SELECT COUNT(1) FROM [#holdStuff])
DECLARE #loopCount INT
SET #loopCount = 1
-- While loop variables
DECLARE #id INT
DECLARE #someInt INT
DECLARE #someBool BIT
DECLARE #otherStuff VARCHAR(200)
-- Loop through item in #holdStuff
WHILE (#loopCount <= #tableCount)
BEGIN
-- Increment the loopCount variable
SET #loopCount = #loopCount + 1
-- Grab the top unprocessed record
SELECT TOP 1
#id = id ,
#someInt = someInt ,
#someBool = someBool ,
#otherStuff = otherStuff
FROM #holdStuff
WHERE isIterated = 0
-- Update the grabbed record to be iterated
UPDATE #holdAccounts
SET isIterated = 1
WHERE id = #id
-- Execute your stored procedure
EXEC someRandomSp #someInt, #someBool, #otherStuff
END
[/code]
Note that you don't need the identity or the isIterated column on your temp/variable table, i just prefer to do it this way so i don't have to delete the top record from the collection as i iterate through the loop.

How to create procedure with multiple string select query in sql?

I want to create procedure with multiple string select query.I want to insert data to table variable and join that temp table with other table.
I don't want to create temp table as real tables. I want to insert data to memory temp table.
Here is my procedure,
CREATE PROCEDURE sp_TempBatch
AS
DECLARE #TempBatchSerial TABLE
(
ID int,
Name nvarchar(200),
StockType nvarchar(50),
ItemNo nvarchar(50)
)
DECLARE #TempQuery as nvarchar(MAX)='',
#VendorQuery as nvarchar(MAX)=''
BEGIN
SET #TempQuery='SELECT ID,Name,'
IF StockType = '1'
BEGIN
SET #TempQuery += ' ''Batch'' as StockType,'
END
ELSE
BEGIN
SET #TempQuery += ' ''Serial'' as StockType,'
END
SET #TempQuery += 'ItemNo INTO #TempBatchSerial
FROM Stock'
EXEC (#TempQuery)
SET #VendorQuery+=' SELECT #TempBatchSerial.* FROM #TempBatchSerial
INNER JOIN Vendor
ON #TempBatchSerial.ID = Vendor.ID
INNER JOIN Partner
ON Vendor.parentid = Partner.syskey'
EXEC (#VendorQuery)
END
When execute procedure show error message of Must declare the table variable "#TempBatchSerial"
You have to refer to #tempBatchSerial via an Alias
That's the only way #tempTables can be referred or linked to.
SELECT T.* FROM #TempBatchSerial T
INNER JOIN Vendor
ON T.ID = Vendor.ID
INNER JOIN Partner
ON Vendor.parentid = Partner.syskey
If that doesn't work you can try to put the #tempTable in the #vendorQuery text.

SQL while loop with Temp Table

I need to create a temporary table and then update the original table. Creating the temporary table is not a problem.
create table #mod_contact
(
id INT IDENTITY NOT NULL PRIMARY KEY,
SiteID INT,
Contact1 varchar(25)
)
INSERT INTO #mod_contact (SiteID, Contact1)
select r.id, r.Contact from dbo.table1 r where CID = 142
GO
Now I need to loop through the table and update r.contact = SiteID + r.contact
I have never used a while loop before and can't seem to make any examples I have seen work.
You can do this in multiple ways, but I think you're looking for a way using a cursor.
A cursor is sort of a pointer in a table, which when incremented points to the next record. ( it's more or less analogeous to a for-next loop )
to use a cursor you can do the following:
-- DECLARE the cursor
DECLARE CUR CURSOR FAST_FORWARD READ_ONLY FOR SELECT id, siteId, contract FROM #mod_contract
-- DECLARE some variables to store the values in
DECLARE #varId int
DECLARE #varSiteId int
DECLARE #varContract varchar(25)
-- Use the cursor
OPEN CUR
FETCH NEXT FROM CUR INTO #varId, #varSiteId, #varContract
WHILE ##FETCH_STATUS = 0
BEGIN
UPDATE dbo.table1
SET contract = #varSiteId + #varContract -- It might not work due to the different types
WHERE id = #varId
FETCH NEXT FROM CUR INTO #varId, #varSiteId, #varContract
END
CLOSE CUR
DEALLOCATE CUR
It's not the most efficient way to get this done, but I think this is what you where looking for.
Hope it helps.
Use a set based approach - no need to loop (from the little details):
UPDATE
r
SET
r.Contact = m.SiteID + r.Contact
FROM
table1 r
INNER JOIN
#mod_contact m
ON m.id=r.id
Your brain wants to do this:
while records
update(i); //update record i
records = records + 1
end while
SQL is set based and allows you to take a whole bunch of records and update them in a single command. The beauty of this is you can use the WHERE clause to filter certain rows that are not needed.
As others have mentioned, learning how to do loops in SQL is generally a bad idea; however, since you're trying to understand how to do something, here's an example:
DECLARE #id int
SELECT #ID =1
WHILE #ID <= (SELECT MAX(ID) FROM table_1)
-- while some condition is true, then do the following
--actions between the BEGIN and END
BEGIN
UPDATE table_1
SET contact = CAST(siteID as varchar(100)) + contact
WHERE table_1.CID = #ID
--increment the step variable so that the condition will eventually be false
SET #ID = #ID + 1
END
--do something else once the condition is satisfied
PRINT 'DONE!! Don't try this in production code...'
Try this one:
-- DECLARE the cursor
DECLARE CUR CURSOR FAST_FORWARD READ_ONLY FOR SELECT column1,column2 FROM table
-- DECLARE some variables to store the values in
DECLARE #varId int
DECLARE #varSiteId int
--DECLARE #varContract varchar(25)
-- Use the cursor
OPEN CUR
FETCH NEXT FROM CUR INTO #varId, #varSiteId
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT *
FROM Table2
WHERE column1 = #varId
AND column2 = #varSiteId
FETCH NEXT FROM CUR INTO #varId, #varSiteId
END
CLOSE CUR
DEALLOCATE CUR
need to create a temporary table and then up date the original table.
Why use a temporary table at all? Your CID column doesn't appear in the temporary table, so I don't see how you can successfully update the original table using SiteID, unless there is only one row where CID = 142 in which using a temp table is definitely overkill.
You can just do this:
UPDATE dbo.table1
SET contact = SiteID + contact
WHERE CID = 142;
Here's a related example which may help getting you to 'think in SQL':
UPDATE T
SET A = B, B = A;
Assuming A and B are of the same type, this would successfully swap their values.

SQL Call Stored Procedure for each Row without using a cursor

How can one call a stored procedure for each row in a table, where the columns of a row are input parameters to the sp without using a Cursor?
Generally speaking I always look for a set based approach (sometimes at the expense of changing the schema).
However, this snippet does have its place..
-- Declare & init (2008 syntax)
DECLARE #CustomerID INT = 0
-- Iterate over all customers
WHILE (1 = 1)
BEGIN
-- Get next customerId
SELECT TOP 1 #CustomerID = CustomerID
FROM Sales.Customer
WHERE CustomerID > #CustomerId
ORDER BY CustomerID
-- Exit loop if no more customers
IF ##ROWCOUNT = 0 BREAK;
-- call your sproc
EXEC dbo.YOURSPROC #CustomerId
END
You could do something like this: order your table by e.g. CustomerID (using the AdventureWorks Sales.Customer sample table), and iterate over those customers using a WHILE loop:
-- define the last customer ID handled
DECLARE #LastCustomerID INT
SET #LastCustomerID = 0
-- define the customer ID to be handled now
DECLARE #CustomerIDToHandle INT
-- select the next customer to handle
SELECT TOP 1 #CustomerIDToHandle = CustomerID
FROM Sales.Customer
WHERE CustomerID > #LastCustomerID
ORDER BY CustomerID
-- as long as we have customers......
WHILE #CustomerIDToHandle IS NOT NULL
BEGIN
-- call your sproc
-- set the last customer handled to the one we just handled
SET #LastCustomerID = #CustomerIDToHandle
SET #CustomerIDToHandle = NULL
-- select the next customer to handle
SELECT TOP 1 #CustomerIDToHandle = CustomerID
FROM Sales.Customer
WHERE CustomerID > #LastCustomerID
ORDER BY CustomerID
END
That should work with any table as long as you can define some kind of an ORDER BY on some column.
DECLARE #SQL varchar(max)=''
-- MyTable has fields fld1 & fld2
Select #SQL = #SQL + 'exec myproc ' + convert(varchar(10),fld1) + ','
+ convert(varchar(10),fld2) + ';'
From MyTable
EXEC (#SQL)
Ok, so I would never put such code into production, but it does satisfy your requirements.
I'd use the accepted answer, but another possibility is to use a table variable to hold a numbered set of values (in this case just the ID field of a table) and loop through those by Row Number with a JOIN to the table to retrieve whatever you need for the action within the loop.
DECLARE #RowCnt int; SET #RowCnt = 0 -- Loop Counter
-- Use a table variable to hold numbered rows containg MyTable's ID values
DECLARE #tblLoop TABLE (RowNum int IDENTITY (1, 1) Primary key NOT NULL,
ID INT )
INSERT INTO #tblLoop (ID) SELECT ID FROM MyTable
-- Vars to use within the loop
DECLARE #Code NVarChar(10); DECLARE #Name NVarChar(100);
WHILE #RowCnt < (SELECT COUNT(RowNum) FROM #tblLoop)
BEGIN
SET #RowCnt = #RowCnt + 1
-- Do what you want here with the data stored in tblLoop for the given RowNum
SELECT #Code=Code, #Name=LongName
FROM MyTable INNER JOIN #tblLoop tL on MyTable.ID=tL.ID
WHERE tl.RowNum=#RowCnt
PRINT Convert(NVarChar(10),#RowCnt) +' '+ #Code +' '+ #Name
END
Marc's answer is good (I'd comment on it if I could work out how to!)
Just thought I'd point out that it may be better to change the loop so the SELECT only exists once (in a real case where I needed to do this, the SELECT was quite complex, and writing it twice was a risky maintenance issue).
-- define the last customer ID handled
DECLARE #LastCustomerID INT
SET #LastCustomerID = 0
-- define the customer ID to be handled now
DECLARE #CustomerIDToHandle INT
SET #CustomerIDToHandle = 1
-- as long as we have customers......
WHILE #LastCustomerID <> #CustomerIDToHandle
BEGIN
SET #LastCustomerId = #CustomerIDToHandle
-- select the next customer to handle
SELECT TOP 1 #CustomerIDToHandle = CustomerID
FROM Sales.Customer
WHERE CustomerID > #LastCustomerId
ORDER BY CustomerID
IF #CustomerIDToHandle <> #LastCustomerID
BEGIN
-- call your sproc
END
END
If you can turn the stored procedure into a function that returns a table, then you can use cross-apply.
For example, say you have a table of customers, and you want to compute the sum of their orders, you would create a function that took a CustomerID and returned the sum.
And you could do this:
SELECT CustomerID, CustomerSum.Total
FROM Customers
CROSS APPLY ufn_ComputeCustomerTotal(Customers.CustomerID) AS CustomerSum
Where the function would look like:
CREATE FUNCTION ComputeCustomerTotal
(
#CustomerID INT
)
RETURNS TABLE
AS
RETURN
(
SELECT SUM(CustomerOrder.Amount) AS Total FROM CustomerOrder WHERE CustomerID = #CustomerID
)
Obviously, the example above could be done without a user defined function in a single query.
The drawback is that functions are very limited - many of the features of a stored procedure are not available in a user-defined function, and converting a stored procedure to a function does not always work.
For SQL Server 2005 onwards, you can do this with CROSS APPLY and a table-valued function.
Using CROSS APPLY in SQL Server 2005
Just for clarity, I'm referring to those cases where the stored procedure can be converted into a table valued function.
This is a variation on the answers already provided, but should be better performing because it doesn't require ORDER BY, COUNT or MIN/MAX. The only disadvantage with this approach is that you have to create a temp table to hold all the Ids (the assumption is that you have gaps in your list of CustomerIDs).
That said, I agree with #Mark Powell though that, generally speaking, a set based approach should still be better.
DECLARE #tmp table (Id INT IDENTITY(1,1) PRIMARY KEY NOT NULL, CustomerID INT NOT NULL)
DECLARE #CustomerId INT
DECLARE #Id INT = 0
INSERT INTO #tmp SELECT CustomerId FROM Sales.Customer
WHILE (1=1)
BEGIN
SELECT #CustomerId = CustomerId, #Id = Id
FROM #tmp
WHERE Id = #Id + 1
IF ##rowcount = 0 BREAK;
-- call your sproc
EXEC dbo.YOURSPROC #CustomerId;
END
This is a variation of n3rds solution above. No sorting by using ORDER BY is needed, as MIN() is used.
Remember that CustomerID (or whatever other numerical column you use for progress) must have a unique constraint. Furthermore, to make it as fast as possible CustomerID must be indexed on.
-- Declare & init
DECLARE #CustomerID INT = (SELECT MIN(CustomerID) FROM Sales.Customer); -- First ID
DECLARE #Data1 VARCHAR(200);
DECLARE #Data2 VARCHAR(200);
-- Iterate over all customers
WHILE #CustomerID IS NOT NULL
BEGIN
-- Get data based on ID
SELECT #Data1 = Data1, #Data2 = Data2
FROM Sales.Customer
WHERE [ID] = #CustomerID ;
-- call your sproc
EXEC dbo.YOURSPROC #Data1, #Data2
-- Get next customerId
SELECT #CustomerID = MIN(CustomerID)
FROM Sales.Customer
WHERE CustomerID > #CustomerId
END
I use this approach on some varchars I need to look over, by putting them in a temporary table first, to give them an ID.
If you don't what to use a cursor I think you'll have to do it externally (get the table, and then run for each statement and each time call the sp)
it Is the same as using a cursor, but only outside SQL.
Why won't you use a cursor ?
I usually do it this way when it's a quite a few rows:
Select all sproc parameters in a dataset with SQL Management Studio
Right-click -> Copy
Paste in to excel
Create single-row sql statements with a formula like '="EXEC schema.mysproc #param=" & A2' in a new excel column. (Where A2 is your excel column containing the parameter)
Copy the list of excel statements into a new query in SQL Management Studio and execute.
Done.
(On larger datasets i'd use one of the solutions mentioned above though).
DELIMITER //
CREATE PROCEDURE setFakeUsers (OUT output VARCHAR(100))
BEGIN
-- define the last customer ID handled
DECLARE LastGameID INT;
DECLARE CurrentGameID INT;
DECLARE userID INT;
SET #LastGameID = 0;
-- define the customer ID to be handled now
SET #userID = 0;
-- select the next game to handle
SELECT #CurrentGameID = id
FROM online_games
WHERE id > LastGameID
ORDER BY id LIMIT 0,1;
-- as long as we have customers......
WHILE (#CurrentGameID IS NOT NULL)
DO
-- call your sproc
-- set the last customer handled to the one we just handled
SET #LastGameID = #CurrentGameID;
SET #CurrentGameID = NULL;
-- select the random bot
SELECT #userID = userID
FROM users
WHERE FIND_IN_SET('bot',baseInfo)
ORDER BY RAND() LIMIT 0,1;
-- update the game
UPDATE online_games SET userID = #userID WHERE id = #CurrentGameID;
-- select the next game to handle
SELECT #CurrentGameID = id
FROM online_games
WHERE id > LastGameID
ORDER BY id LIMIT 0,1;
END WHILE;
SET output = "done";
END;//
CALL setFakeUsers(#status);
SELECT #status;
A better solution for this is to
Copy/past code of Stored Procedure
Join that code with the table for which you want to run it again (for each row)
This was you get a clean table-formatted output. While if you run SP for every row, you get a separate query result for each iteration which is ugly.
In case the order is important
--declare counter
DECLARE #CurrentRowNum BIGINT = 0;
--Iterate over all rows in [DataTable]
WHILE (1 = 1)
BEGIN
--Get next row by number of row
SELECT TOP 1 #CurrentRowNum = extendedData.RowNum
--here also you can store another values
--for following usage
--#MyVariable = extendedData.Value
FROM (
SELECT
data.*
,ROW_NUMBER() OVER(ORDER BY (SELECT 0)) RowNum
FROM [DataTable] data
) extendedData
WHERE extendedData.RowNum > #CurrentRowNum
ORDER BY extendedData.RowNum
--Exit loop if no more rows
IF ##ROWCOUNT = 0 BREAK;
--call your sproc
--EXEC dbo.YOURSPROC #MyVariable
END
I had some production code that could only handle 20 employees at a time, below is the framework for the code. I just copied the production code and removed stuff below.
ALTER procedure GetEmployees
#ClientId varchar(50)
as
begin
declare #EEList table (employeeId varchar(50));
declare #EE20 table (employeeId varchar(50));
insert into #EEList select employeeId from Employee where (ClientId = #ClientId);
-- Do 20 at a time
while (select count(*) from #EEList) > 0
BEGIN
insert into #EE20 select top 20 employeeId from #EEList;
-- Call sp here
delete #EEList where employeeId in (select employeeId from #EE20)
delete #EE20;
END;
RETURN
end
I had a situation where I needed to perform a series of operations on a result set (table). The operations are all set operations, so its not an issue, but...
I needed to do this in multiple places. So putting the relevant pieces in a table type, then populating a table variable w/ each result set allows me to call the sp and repeat the operations each time i need to .
While this does not address the exact question he asks, it does address how to perform an operation on all rows of a table without using a cursor.
#Johannes offers no insight into his motivation , so this may or may not help him.
my research led me to this well written article which served as a basis for my solution
https://codingsight.com/passing-data-table-as-parameter-to-stored-procedures/
Here is the setup
drop type if exists cpRootMapType
go
create type cpRootMapType as Table(
RootId1 int
, RootId2 int
)
go
drop procedure if exists spMapRoot2toRoot1
go
create procedure spMapRoot2toRoot1
(
#map cpRootMapType Readonly
)
as
update linkTable set root = root1
from linktable lt
join #map m on lt.root = root2
update comments set root = root1
from comments c
join #map m on c.root = root2
-- ever growing list of places this map would need to be applied....
-- now consolidated into one place
here is the implementation
... populate #matches
declare #map cpRootMapType
insert #map select rootid1, rootid2 from #matches
exec spMapRoot2toRoot1 #map
I like to do something similar to this (though it is still very similar to using a cursor)
[code]
-- Table variable to hold list of things that need looping
DECLARE #holdStuff TABLE (
id INT IDENTITY(1,1) ,
isIterated BIT DEFAULT 0 ,
someInt INT ,
someBool BIT ,
otherStuff VARCHAR(200)
)
-- Populate your #holdStuff with... stuff
INSERT INTO #holdStuff (
someInt ,
someBool ,
otherStuff
)
SELECT
1 , -- someInt - int
1 , -- someBool - bit
'I like turtles' -- otherStuff - varchar(200)
UNION ALL
SELECT
42 , -- someInt - int
0 , -- someBool - bit
'something profound' -- otherStuff - varchar(200)
-- Loop tracking variables
DECLARE #tableCount INT
SET #tableCount = (SELECT COUNT(1) FROM [#holdStuff])
DECLARE #loopCount INT
SET #loopCount = 1
-- While loop variables
DECLARE #id INT
DECLARE #someInt INT
DECLARE #someBool BIT
DECLARE #otherStuff VARCHAR(200)
-- Loop through item in #holdStuff
WHILE (#loopCount <= #tableCount)
BEGIN
-- Increment the loopCount variable
SET #loopCount = #loopCount + 1
-- Grab the top unprocessed record
SELECT TOP 1
#id = id ,
#someInt = someInt ,
#someBool = someBool ,
#otherStuff = otherStuff
FROM #holdStuff
WHERE isIterated = 0
-- Update the grabbed record to be iterated
UPDATE #holdAccounts
SET isIterated = 1
WHERE id = #id
-- Execute your stored procedure
EXEC someRandomSp #someInt, #someBool, #otherStuff
END
[/code]
Note that you don't need the identity or the isIterated column on your temp/variable table, i just prefer to do it this way so i don't have to delete the top record from the collection as i iterate through the loop.