I have a need to monitor a subset of fields on a table and perform a task when one of them changes.
I am using a trigger on the table update which and then am looking at the changes as follows:
-- join the deleted and inserted to get a full list of rows
select * into #tmp from (select * from inserted union select * from deleted) un
-- select a count of differing rows, > 1 means something is different
select distinct count(*) from #tmp
This is fine and a count of 2 or more means something is different on single line updates. Issue is if I am doing a multiple line update then this breaks down.
Is there a way I can get this to work for a multi line update or do I need to try a different approach completely.
You could do something like this (syntax completely untested)
IF NOT UPDATE(col)
RETURN
SELECT inserted.key, inserted.col as i_col, deleted.col as d_col
INTO #interestingrows
FROM inserted JOIN deleted on inserted.key = deleted.key
and inserted.col <> deleted.col /*If col is nullable cater for that as well*/
IF ##ROWCOUNT=0
RETURN
/*Process contents of #interestingrows*/
I ended up with a fairly simple solution. I wrote an additional loop around the check that did the check per line in inserted.
-- get a list of updated line id's
select field1 as id into #loop from inserted
-- loop through all the id's and do a compare
while (select count(*) from #loop) > 0 begin
select top 1 #id = id from #loop
select * into #tmp from (select * from inserted where field1 = #id union
select * from deleted where field1 = #id) un
-- do a select ditinct to count the differing lines.
if (select distinct count(*) from #tmp) > 1 begin
-- the 2 lines don't match, so mark for update
update test1 set flag = 1 where field1 = #id
end
drop table #tmp
delete #loop where id = #id
end
Related
I have a table [Order] that has records with sequential ID (in odd number only, i.e. 1,3,5,7...989, 991, 993, 995, 997, 999), it is seen that a few records were accidentally deleted and should be inserted back, first thing is to find out what records are missing in the current table, there are hundreds of records in this table
Don't know how to write the query, can anyone kindly help, please?
I am thinking if I have to write a stored procedure or function but would be better if I can avoid them for environment reasons.
Below peuso code is what I am thinking:
set #MaxValue = Max(numberfield)
set #TestValue = 1
open cursor on recordset ordered by numberfield
foreach numberfield
while (numberfield != #testvalue) and (#testvalue < #MaxValue) then
Insert #testvalue into #temp table
set #testvalue = #textvalue + 2
Next
Next
UPDATE:
Expected result:
Order ID = 7 should be picked up as the only missing record.
Update 2:
If I use
WHERE
o.id IS NULL;
It returns nothing:
Since I didn't get a response from you, in the comments, I've altered the script for you to fill in accordingly:
declare #id int
declare #maxid int
set #id = 1
select #maxid = max([Your ID Column Name]) from [Your Table Name]
declare #IDseq table (id int)
while #id < #maxid --whatever you max is
begin
insert into #IDseq values(#id)
set #id = #id + 1
end
select
s.id
from #IDseq s
left join [Your Table Name] t on s.id = t.[Your ID Column Name]
where t.[Your ID Column Name] is null
Where you see [Your ID Column Name], replace everything with your column name and the same goes for [Your Table Name].
I'm sure this will give you the results you seek.
We can try joining to a number table, which contains all the odd numbers which you might expect to appear in your own table.
DECLARE #start int = 1
DECLARE #end int = 1000
WITH cte AS (
SELECT #start num
UNION ALL
SELECT num + 2 FROM cte WHERE num < #end
)
SELECT num
FROM cte t
LEFT JOIN [Order] o
ON t.num = o.numberfield
WHERE
o.numberfield IS NULL;
I have a straight forward SQL query that I am working with and trying to figure out the best way to approach the where clause.
Essentially, there are two temp tables created and if there is data in the XML string passed to the stored procedure, those tables are populated.
My where clause needs to check these temp tables for data, and if there is no data, it ignores them like they are not there and fetches all data.
-- Create temp tables to hold our XML filter criteria
DECLARE #users AS TABLE (QID VARCHAR(10))
DECLARE #dls AS TABLE (dlName VARCHAR(50))
-- Insert our XML filters
IF #xml.exist('/root/data/users') > 0
BEGIN
INSERT INTO #users( QID )
SELECT ParamValues.x1.value('QID[1]', 'varchar(10)')
FROM #xml.nodes('/root/data/users/user') AS ParamValues(x1)
END
IF #xml.exist('/root/data/dls') > 0
BEGIN
INSERT INTO #dls( dlName )
SELECT ParamValues.x1.value('dlName[1]', 'varchar(50)')
FROM #xml.nodes('/root/data/dld/dl') AS ParamValues(x1)
END
-- Fetch our document details based on the XML provided
SELECT d.documentID ,
d.sopID ,
d.documentName ,
d.folderLocation ,
d.userGroup ,
d.notes
FROM dbo.Documents AS d
LEFT JOIN dbo.DocumentContacts AS dc
ON dc.documentID = d.documentID
LEFT JOIN dbo.DocumentContactsDLs AS dl
ON dl.documentID = d.documentID
-- How can I make these two logic checks work only if there is data, otherwise, include everything.
WHERE dc.QID IN (SELECT QID FROM #users)
AND dl.DL IN (SELECT dlName FROM #dls)
FOR XML PATH ('data'), ELEMENTS, TYPE, ROOT('root');
In the query above, I am trying to used the data in the temp tables only if there is data in them, otherwise, it needs to act like that where statement isn't there for that specific value and include records regardless.
Example: If only #users had data, it would ignore AND dl.DL IN (SELECT dlName FROM #dls) and get everything, regardless of what was in the DL column on those joined records.
Use NOT EXISTS to check the existence of any record in variable table. Here is one way
WHERE ( dc.QID IN (SELECT QID FROM #users)
OR NOT EXISTS (SELECT 1 FROM #users) )
AND ( dl.DL IN (SELECT dlName FROM #dls)
OR NOT EXISTS (SELECT 1 FROM #dls) )
Try this. But please note that I did not get a chance to test it properly and I believe that you want to check the values in #users first and if there is no record existing in that table, then you want to check with the entries in #dls. Also if there are no entries in both of these tables, then you want to skip both the tables.
DECLARE #fl bit = 0
SELECT #fl = CASE WHEN EXISTS (SELECT 1 FROM #users) THEN
1
WHEN EXISTS (SELECT 1 FROM #dls) THEN
2
ELSE
0
END
WHERE ( (dc.QID IN (SELECT QID FROM #users) AND #fl = 1)
OR
(dl.DL IN (SELECT dlName FROM #dls) AND #fl = 2)
OR (1=1 AND #fl = 0)
)
I am trying to use while loop instead of CURSOR in SQL SERVER. I am trying to select TOP 1 in while and set them to the variables like below. It doesnt let me set the variables in while loop. What am I doing wrong?
WHILE (
SELECT TOP 1 #WAOR_CODE = WAOR_.WAOR_CODE
, #WAOD_INVENTORYITEMID = WAOD_.WAOD_INVENTORYITEMID
FROM #wmsorder
)
BEGIN
SELECT #WAOR_CODE
, #WAOD_INVENTORYITEMID
DELETE TOP (1) #wmsorder
END
Another option:
WHILE EXISTS(select 1 FROM #wmsorder)
BEGIN
DELETE TOP (1)
FROM #wmsorder
END
However, deleting all records from a table one by one might be a performance hell. You might want to consider using TRUNCATE TABLE instead:
TRUNCATE TABLE #wmsorder
Also, note that each delete is written to the database log, while truncate table doesn't get written to the log at all.
Testing with a temporary table containing 100,000 rows, deleting the rows one by one took me 9 seconds, while truncate table completed immediately:
-- create and populate sample table
SELECT TOP 100000 IDENTITY(int,1,1) AS Number
INTO #wmsorder
FROM sys.objects s1
CROSS JOIN sys.objects s2
-- delete rows one by one
WHILE EXISTS(select 1 FROM #wmsorder)
BEGIN
DELETE TOP (1)
FROM #wmsorder
END
-- clean up
DROP TABLE #wmsorder
-- create and populate sample table
SELECT TOP 100000 IDENTITY(int,1,1) AS Number
INTO #wmsorder
FROM sys.objects s1
CROSS JOIN sys.objects s2
-- truncate the table
TRUNCATE TABLE #wmsorder
-- clean up
DROP TABLE #wmsorder
DECLARE #t TABLE (a INT PRIMARY KEY)
INSERT INTO #t
VALUES (1), (2), (3)
Variant #1:
label:
DELETE TOP(1)
FROM #t
OUTPUT DELETED.a
IF ##ROWCOUNT > 0
GOTO label
Variant #2:
WHILE ##ROWCOUNT != 0
DELETE TOP(1)
FROM #t
OUTPUT DELETED.a
Variant #3:
DECLARE #a TABLE(a INT)
WHILE ##ROWCOUNT != 0 BEGIN
DELETE FROM #a
DELETE TOP(1)
FROM #t
OUTPUT DELETED.a INTO #a
SELECT * FROM #a
END
See the below code. I just corrected the SQL statements shared by you
WHILE 1=1
BEGIN
IF NOT EXISTS (SELECT 1 FROM #wmsorder)
BREAK
SELECT TOP 1 #WAOR_CODE = WAOR_.WAOR_CODE
,#WAOD_INVENTORYITEMID = WAOD_.WAOD_INVENTORYITEMID
FROM #wmsorder WAOR_
SELECT #WAOR_CODE
,#WAOD_INVENTORYITEMID
DELETE #wmsorder WHERE WAOR_CODE = #WAOR_CODE AND WAOD_INVENTORYITEMID = #WAOD_INVENTORYITEMID
END
But as Zohar Peled mentioned, it will be a pain to the engine if you are deleting the records one by one from a table. So below I have shared another query, through this even you can track the records before deleting from the table
DECLARE #TableVar AS TABLE (WAOR_CODE VARCHAR(100), WAOD_INVENTORYITEMID VARCHAR(100))
WHILE 1=1
BEGIN
SELECT TOP 1 #WAOR_CODE = WAOR_.WAOR_CODE
,#WAOD_INVENTORYITEMID = WAOD_.WAOD_INVENTORYITEMID
FROM #wmsorder WAOR_
WHERE NOT EXISTS (SELECT 1 FROM #TableVar t WHERE t.WAOR_CODE = WAOR_.WAOR_CODE AND t.WAOD_INVENTORYITEMID = WAOR_.WAOD_INVENTORYITEMID)
IF #WAOR_CODE IS NULL AND #WAOD_INVENTORYITEMID IS NULL
BREAK
INSERT INTO #TableVar
(WAOR_CODE, WAOD_INVENTORYITEMID)
SELECT #WAOR_CODE
,#WAOD_INVENTORYITEMID
END
DELETE #wmsorder WHERE EXISTS (SELECT 1 FROM #TableVar t WHERE t.WAOR_CODE = #wmsorder.WAOR_CODE AND t.WAOD_INVENTORYITEMID = #wmsorder.WAOD_INVENTORYITEMID)
Sorry I did not test the second code. Please forgive me if it breaks something. But I am pretty sure it may require a small repair to make this query functional. All the best.
Following is what my logic is supposed to do
IF #id = 1
BEGIN
SELECT * INTO #abc from table1
END
IF #id = 2
BEGIN
SELECT * INTO #abc frm table2
END
However, when I execute my statements I get the error saying
there is already an object named #abc..
Any suggestions to overcome this error please?
You can't. The parser doesn't understand your IF logic and it treats both SELECT INTO statements as things that will happen.
What you should do is:
IF #id = 1
BEGIN
SELECT * INTO #abc1 from table1
END
IF #id = 2
BEGIN
SELECT * INTO #abc2 frm table2
END
IF #id = 1
SELECT * FROM #abc1;
ELSE
SELECT * FROM #abc2;
After all, you need to know the different columns that are in the #temp table in order to do anything meaningful with it, right?
(Or avoid temp tables altogether.)
Another possible solution:
CREATE TABLE #abc (
--put schema here
)
IF #id = 1
BEGIN
insert into #abc
select * from table1
END
IF #id = 2
BEGIN
insert into #abc
select * from table2
END
select * from #abc
drop table #abc;
You should always use the column names instead of * because it's better in terms of performance.
And also, select * finds all the columns currently in a table, changes in the structure of a table such as adding, removing, or renaming columns automatically modify the results of select *. Listing columns individually gives you more precise control over the results.
SQL SERVER 2000:
I have a table with test data (about 100000 rows), I want to update a column value from another table with some random data from another table. According to this question, This is what I am trying:
UPDATE testdata
SET type = (SELECT TOP 1 id FROM testtypes ORDER BY CHECKSUM(NEWID()))
-- or even
UPDATE testdata
SET type = (SELECT TOP 1 id FROM testtypes ORDER BY NEWID())
However, the "type" field is still with the same value for all rows; Any ideas what Am I doing wrong?
[EDIT]
I would expect this query to return one different value for each row, but it doesn't:
SELECT testdata.id, (SELECT TOP 1 id FROM testtypes ORDER BY CHECKSUM(NEWID())) type
FROM testdata
-- however seeding a rand value works
SELECT testdata.id, (SELECT TOP 1 id FROM testtypes ORDER BY CHECKSUM(NEWID()) + RAND(testdata.id)) type
FROM testdata
Your problem is: you are selecting only a single value and then updating all columns with that one single value.
In order to really get a randomization going, you need to do a step-by-step / looping approach - I tried this in SQL Server 2008, but I think it should work in SQL Server 2000 as well:
-- declare a temporary TABLE variable in memory
DECLARE #Temporary TABLE (ID INT)
-- insert all your ID values (the PK) into that temporary table
INSERT INTO #Temporary SELECT ID FROM dbo.TestData
-- check to see we have the values
SELECT COUNT(*) AS 'Before the loop' FROM #Temporary
-- pick an ID from the temporary table at random
DECLARE #WorkID INT
SELECT TOP 1 #WorkID = ID FROM #Temporary ORDER BY NEWID()
WHILE #WorkID IS NOT NULL
BEGIN
-- now update exactly one row in your base table with a new random value
UPDATE dbo.TestData
SET [type] = (SELECT TOP 1 id FROM dbo.TestTypes ORDER BY NEWID())
WHERE ID = #WorkID
-- remove that ID from the temporary table - has been updated
DELETE FROM #Temporary WHERE ID = #WorkID
-- first set #WorkID back to NULL and then pick a new ID from
-- the temporary table at random
SET #WorkID = NULL
SELECT TOP 1 #WorkID = ID FROM #Temporary ORDER BY NEWID()
END
-- check to see we have no more IDs left
SELECT COUNT(*) AS 'After the update loop' FROM #Temporary
you need to enforce a per row calculation in the selection of the new ids ..
this would do the trick
UPDATE testdata
SET type = (SELECT TOP 1 id FROM testtypes ORDER BY outerTT*CHECKSUM(NEWID()))
FROM testtypes outerTT