I have the below code where I assign an unique ID to each row which contains a current code and a previous code. It seems to be working fine but my question is if I have an updated file with new codes, how do I resume the unique ID from where it was left off?
For example, how do I populate the below ID highlighted in yellow if I add these additional row?
Example
CREATE PROCEDURE [dbo].[PI_Key_Create_Update] AS
BEGIN
Truncate Table RB_PI_Key_Assign
Truncate Table RB_PI_Key_Link
INSERT INTO RB_PI_Key_Assign
SELECT
ROW_NUMBER() OVER (ORDER BY RB_Code_L) AS PI_Key
, RB_Code_L
, RB_Code_L_P
FROM Stage_RB_Previous
INSERT INTO RB_PI_Key_Link
SELECT
a.PI_Key
, b.PI_Key as PI_KEY_P
, a.RB_Code_L
, a.RB_Code_L_P
FROM RB_PI_Key_Assign a LEFT JOIN RB_PI_Key_Assign b ON (a.RB_Code_L_P=b.RB_Code_L)
END
Thanks
first and foremost this type of columns should be identity seeded or autoincrement. You don't need to maintain them.
There is nothing special if you have them manually updated for no reason at all.
Related
Sorry for the long question/post but need some help as I've been searching for several days but havent found anything that helps. Seems like it should be easy but..here goes
I have table1 in my (Access 2010) database that has exising records. I have another table2 that after I run a query, it first deletes the data in table 2, then imports new records into that table. I run the import into table 2 on a semi regular basis but have yet to copy all those records into table 1 successfully.
I need to copy only the records from table 2 to table 1 if the records don't already exist in table1. So, each time the query or vba code would run, it would be continuing to grow table 1 without duplicating existing data.
To clarify further, it's data from the Outlook GAL so each time table2 imports that data (lname,fname,phone,email) it needs to be added to table1, but only if it doesn't already exist in table 1.
I have a small start of SQL but cannot get it to work properly because I'm not sure how to add the other fields into this SQL statement properly (unfortunately I don't know a whole lot about SQL or creating an append query):
INSERT INTO [Current] ( FirstName )
SELECT DISTINCT tblglobaladdresslistimport.First
FROM tblglobaladdresslistimport LEFT JOIN [Current] ON tblglobaladdresslistimport.First = Current.FirstName
WHERE Current.FirstName Is Null;
How about this :
INSERT INTO [Current](FirstName, LastName, Phone, Email)
SELECT DISTINCT
tblglobaladdresslistimport.First
, tblglobaladdresslistimport.Last
, tblglobaladdresslistimport.Phone
, tblglobaladdresslistimport.Email
FROM
tblglobaladdresslistimport LEFT JOIN [Current]
ON tblglobaladdresslistimport.First = Current.FirstName
AND tblglobaladdresslistimport.Last = Current.LastName
AND tblglobaladdresslistimport.Phone = Current.Phone
AND tblglobaladdresslistimport.Email = Current.Email
WHERE Current.FirstName Is Null
AND Current.LastName Is Null
AND Current.Phone Is Null
AND Current.Email Is Null;
Adjust column names if I guessed it wrong. That assumed that you don't have primary key, so data in tblglobaladdresslistimport considered already exists if there is a row in Current having same value for all columns.
I am trying to insert missing rows into a table. One of the columns is OrderNumber (sort number), this column should be +1 of the max value of OrderNumber returned for sID in the table. Some sIDs do not appear in the SPOL table which is why there is the WHERE clause at the end of the statement. I would run this statement again but set OrderNumber to 1 for the records where sID does not currently exist in the table.
The statement below doesn't work due to the OrderNumber causing issues with the primary key which is sID + OrderNumber.
How can I get the OrderNumber to increase for each row that is inserted based on the sID column?
INSERT INTO SPOL(sID, OrderNumber, oID)
SELECT
sID, OrderNumber, oID
FROM
(SELECT
sID,
(SELECT Max(OrderNumber) + 1
FROM SPOL
WHERE sID = TMPO.sID) AS OrderNumber,
oID
FROM TMPO
WHERE NOT EXISTS (SELECT * FROM SPOL
WHERE SPOL.oID = TMPO.oID)
) AS MyData
WHERE
OrderNumber IS NOT NULL
It's much better to handle this in the database design with an identity column - you don't mention whether or not you can change the schema but hopefully you can as queries will end up a lot cleaner if you don't have to manage it yourself.
You can set the Identity property to on for your OrderNumber column in SQL Server management studio, but the script it would generate clones the table with the new specification, inserts the values you've already got with Identity_Insert on, drops the original table, and renames the temporary one to replace it - this has massive overheads depending on how many rows you've got.
The most efficient way to go about it is probably:
create an additional column with the identity property on
copy across the values
rename the original column
rename the new column to the same name as the original
remove the original OrderNumber column
Once it's done, it's done though - and looks after itself. Wouldn't you rather your insert statement simply said something like this:
INSERT INTO SPOL (sID, oID)
SELECT sID, oID,
FROM TMPO
WHERE OrderNumber IS NOT NULL
Use identity(1,1) to increment your column Order Number,this would makes your task easy..!
The reason I need this for is that I made a column on my table called display_order, for now it's smallint and the numbers were pre-determined.
However, when I insert a new record with my software I don't know how to get the highest number in that column and add 1, so I thought about the possibility of an auto-incremented column where if I change 8 to 9 it will change everything else accordingly.
Is this possible?
The answer to your question is "No" IDENTITY is the only auto incrementing capability (and these columns are not updatable)
But if this is a display_order field can't you just make it float to allow you to insert items between other items rather than having to shift all other items down to create a gap?
However, when I insert a new record with my software I don't know how to get the highest number in that column and add 1,
Insert MyTable( display_order, .... )
Select (
Select Max(display_order) + 1
From MyTable As T1
), ...
From MyTable
However, I wouldn't recommend this. If display_order is user settable, then I would simply assume relative values. Thus, it wouldn't matter if a user added two values with a display_order = 0. If you really want to go the extra mile and provide the ability to resequence the display_order, you could do it like so:
Update MyTable
Set display_order = Z.NewSeq
From (
Select PKCol
, Row_Number() Over ( Order By display_order ) As NewSeq
From MyTable
) As Z
Join MyTable As T
On T.PKCol = Z.PKCol
Because you only get one IDENTITY column per table, I would probably use a trigger or other mechanism (if there's a centralized insertion stored proc) to default it to one more than the highest number in the table if not provided. This avoids having to SET IDENTITY_INSERT or anything like that.
Sybase db tables do not have a concept of self updating row numbers. However , for one of the modules , I require the presence of rownumber corresponding to each row in the database such that max(Column) would always tell me the number of rows in the table.
I thought I'll introduce an int column and keep updating this column to keep track of the row number. However I'm having problems in updating this column in case of deletes. What sql should I use in delete trigger to update this column?
You can easily assign a unique number to each row by using an identity column. The identity can be a numeric or an integer (in ASE12+).
This will almost do what you require. There are certain circumstances in which you will get a gap in the identity sequence. (These are called "identity gaps", the best discussion on them is here). Also deletes will cause gaps in the sequence as you've identified.
Why do you need to use max(col) to get the number of rows in the table, when you could just use count(*)? If you're trying to get the last row from the table, then you can do
select * from table where column = (select max(column) from table).
Regarding the delete trigger to update a manually managed column, I think this would be a potential source of deadlocks, and many performance issues. Imagine you have 1 million rows in your table, and you delete row 1, that's 999999 rows you now have to update to subtract 1 from the id.
Delete trigger
CREATE TRIGGER tigger ON myTable FOR DELETE
AS
update myTable
set id = id - (select count(*) from deleted d where d.id < t.id)
from myTable t
To avoid locking problems
You could add an extra table (which joins to your primary table) like this:
CREATE TABLE rowCounter
(id int, -- foreign key to main table
rownum int)
... and use the rownum field from this table.
If you put the delete trigger on this table then you would hugely reduce the potential for locking problems.
Approximate solution?
Does the table need to keep its rownumbers up to date all the time?
If not, you could have a job which runs every minute or so, which checks for gaps in the rownum, and does an update.
Question: do the rownumbers have to reflect the order in which rows were inserted?
If not, you could do far fewer updates, but only updating the most recent rows, "moving" them into gaps.
Leave a comment if you would like me to post any SQL for these ideas.
I'm not sure why you would want to do this. You could experiment with using temporary tables and "select into" with an Identity column like below.
create table test
(
col1 int,
col2 varchar(3)
)
insert into test values (100, "abc")
insert into test values (111, "def")
insert into test values (222, "ghi")
insert into test values (300, "jkl")
insert into test values (400, "mno")
select rank = identity(10), col1 into #t1 from Test
select * from #t1
delete from test where col2="ghi"
select rank = identity(10), col1 into #t2 from Test
select * from #t2
drop table test
drop table #t1
drop table #t2
This would give you a dynamic id (of sorts)
I have a temp table with the exact structure of a concrete table T. It was created like this:
select top 0 * into #tmp from T
After processing and filling in content into #tmp, I want to copy the content back to T like this:
insert into T select * from #tmp
This is okay as long as T doesn't have identity column, but in my case it does. Is there any way I can ignore the auto-increment identity column from #tmp when I copy to T? My motivation is to avoid having to spell out every column name in the Insert Into list.
EDIT: toggling identity_insert wouldn't work because the pkeys in #tmp may collide with those in T if rows were inserted into T outside of my script, that's if #tmp has auto-incremented the pkey to sync with T's in the first place.
SET IDENTITY_INSERT ON
INSERT command
SET IDENTITY_INSERT OFF
As identity will be generated during insert anyway, could you simply remove this column from #tmp before inserting the data back to T?
alter table #tmp drop column id
UPD: Here's an example I've tested in SQL Server 2008:
create table T(ID int identity(1,1) not null, Value nvarchar(50))
insert into T (Value) values (N'Hello T!')
select top 0 * into #tmp from T
alter table #tmp drop column ID
insert into #tmp (Value) values (N'Hello #tmp')
insert into T select * from #tmp
drop table #tmp
select * from T
drop table T
See answers here and here:
select * into without_id from with_id
union all
select * from with_id where 1 = 0
Reason:
When an existing identity column is selected into a new table, the new column inherits the IDENTITY property, unless one of the following conditions is true:
The SELECT statement contains a join, GROUP BY clause, or aggregate function.
Multiple SELECT statements are joined by using UNION.
The identity column is listed more than one time in the select list.
The identity column is part of an expression.
The identity column is from a remote data source.
If any one of these conditions is true, the column is created NOT NULL instead of inheriting the IDENTITY property. If an identity column is required in the new table but such a column is not available, or you want a seed or increment value that is different than the source identity column, define the column in the select list using the IDENTITY function. See "Creating an identity column using the IDENTITY function" in the Examples section below.
All credit goes to Eric Humphrey and bernd_k
Not with SELECT * - if you selected every column but the identity, it will be fine. The only way I can see is that you could do this by dynamically building the INSERT statement.
Just list the colums you want to re-insert, you should never use select * anyway. If you don't want to type them ,just drag them from the object browser (If you expand the table and drag the word, columns, you will get all of them, just delete the id column)
INSERT INTO #Table
SELECT MAX(Id) + ROW_NUMBER() OVER(ORDER BY Id)
set identity_insert on
Use this.
Might an "update where T.ID = #tmp.ID" work?
it gives me a chance to preview the data before I do the insert
I have joins between temp tables as part of my calculation; temp tables allows me to focus on the exact set data that I am working with. I think that was it. Any suggestions/comments?
For part 1, as mentioned by Kolten in one of the comments, encapsulating your statements in a transaction and adding a parameter to toggle between display and commit will meet your needs. For Part 2, I would needs to see what "calculations" you are attempting. Limiting your data to a temp table may be over complicating the situation.