Unique Columns And Logical Deletion
May 31, 2007
In tables where reporting or historical information needs to be maintained I find that logical deletion of rows is better than actually deleting the row and any FK relationships. However when one of the columns in the table must be unique this introduces a problem because uniqueness only matters for "active" rows. I'm hoping someone can provide some advice on how to best handle this situation.
Here is an example to work from. Suppose we have a table that contains job positions. The table contains an IDENTITY column for the PK (to avoid duplicating position names), a Name column that must be unique and an IsActive column that is set to 0 when the position has been "deleted". This setup allows for historical reporting to properly pick up the position information even though it might no longer be used in a company. You can substitute your own scenarios here as there are quite a few.
Now if the Name column is marked as a unique column then the DB will enforce integrity which is what we want. However we will want to be able to "delete" a position but later add a new position with the same name. One could argue that we should just "undelete" the original position but that is not often a good idea so assume "undelete" is not an option. Given the unique constraint a new position could not be created if an existing position (active or otherwise) already existed with the same name. We could set up the unique constraint to include the Name and IsActive columns but now we are prevented from ever deleting two positions with the same name.
My initial thought is to create a new UniqueName column that is unique and remove the uniqueness constraint on the Name column. The UniqueName column is set (via a trigger) to the Name column when the position is active. When the position is deleted the trigger changes the UniqueName to include a timestamp or something to ensure uniqueness. This is handled by the system and not exposed to clients.
Any advice or alternatives on this approach (preferably with advantages and disadvantages)? Thanks.
Michael Taylor - 5/31/07
http://p3net.mvps.org
View 4 Replies
ADVERTISEMENT
Apr 7, 2008
Hi,
Te following situtation is :
ReportModel is created ,there is only a named query in DSV ,it has a few tables in it(The relationship are inner joins and outer joins).
The question is how could I create a unique logical primary key to identify each unique row in the named query dataset, and also you cannt generate a model unless the named query has a logical primary key . how can I solve this problem,any help?
View 2 Replies
View Related
Apr 26, 2007
Hi all!
I have been doing some testing with transactional replication. I have a table (TEST) with the following columns:
[id] [int] IDENTITY(1,1) NOT FOR REPLICATION NOT NULL,
[name] [varchar](50) COLLATE SQL_Latin1_General_CP850_CI_AS NULL,
[stock] [int] NOT NULL CONSTRAINT [DF_Prueba1_stock] DEFAULT ((0)),
I want the table rows to have an independent stock value for each database. So,
I made a transactional publication with updatable subscriptions, to replicate all the table columns, except the stock column.
The problem is when I reset subscriptions: the table is deleted an created again on the subscriber, so all the data stored at the stock column is lost. I tried to solve this changing the "Action if name is in use" option at the publication. I choose to keep the current object without changes, but I began having problems with the generation of the identity values at the subscriber.
Any suggestions will be welcomed
Thanks in advance ;-)
View 8 Replies
View Related
Feb 21, 2008
Hi Guys, I came here again to ask something about my application, Is there a way to make 2 columns unique with each other even if they don't have a primary key? If there's a way how? I wanna make a rule so, my application wont replicate its record. Graciaz,Nhoyti
View 3 Replies
View Related
Feb 13, 2004
I use the identity = yes for my unique columns in most of my tables that need it. I am trying to decide if I should change identity = no, and instead manually update my unique number column myself by adding one when I insert new rows.
The reason I want to do this is for maintainabilty and ease of transfering data for backup to other sql servers. I always have trouble keeping the identity numbers to stay the same as they are in the original database because when they are transfered to a db that has identity = yes, the numbers get rearranged.
It will also make it easier to transfer data from original db to another sql server db and use the data right away without having to configure the destination db to disable identity and then enable it, etc.
Any pro's con's appreciated,
Dan
View 8 Replies
View Related
Mar 20, 2013
I have result set as the attached in screenshot, where the candidateid gets duplicated, but then the column university and careerchoice column has different values for the same candidate. (the CareerChoice and University comes from different tables and i have used union clause)
What want is e.g. CandidateId 186 repeats three times, it should be one row, with three columns all filled with the values which are in different rows.
So that I don't have duplicate candidate ids and i have single row with all column data.
View 6 Replies
View Related
Apr 19, 2013
I find to be able to have multiple NULL entries in the following constraint:
Code:
CREATE UNIQUE INDEX my_uidx ON my_table(my_col1,my_col2) WHERE ??? IS NOT NULL;
But is not possible to check multiple columns in "WHERE".
I using SQL Server 2012 Express
View 3 Replies
View Related
Mar 7, 2006
Hi i am designing a database. It will be used by field guys who will insert new records and will replicate at the end of the day with a central database using merge replication. Can anyone tell me if I am choosing wisely or not with the following 3 points:
1. i am going to use a uniqueidentifier value in a column (using newid()) for the merge replication. (I don't care that it's an ugly value as i never plan to look at it.
2. I am using an identity column (INT)to create a unique value within the table
3. I want to create a unique column comprising of data from other columns (e.g. date+identity+salesrep) This gives me an intelligent candidate for a primary key. But I think i have to create this with an instead of trigger (is that right)
many thanks in advance
ICW
View 5 Replies
View Related
May 17, 2007
Using DISTINCT with SELECT have effect only for one column.
But when is needed to select (or to count) queries for all rows for all columns in a table without duplicates, doesn't work.
Select DISTINCT a1,a2,a3,a4 From Y ---> results 167 rows
Select DISTINCT a4 From Y ---> " 85 rows
Any thoughts?
Jorge3921
View 14 Replies
View Related
Feb 12, 2006
Hello.
Could anyone tell me why it is not possible to create a foreign key on two columns those references on 2 columns in another table? Those 2 columns have each a unique constraint.
I have:
CREATE TABLE T_PK (ID1 INT CONSTRAINT CHK_UNIQUE1 UNIQUE,ID2 INT CONSTRAINT CHK_UNIQUE2 UNIQUE)
CREATE TABLE T_FK (ID1 INT, ID2 INT)
And I want to do:
ALTER TABLE T_FK ADD CONSTRAINT CHK_FK FOREIGN KEY (ID1, ID2) REFERENCES T_PK (ID1,ID2)
I see no reason why this is not working because always
a row in the table T_FK referencing only one row in table T_PK.
Thank you.
Have a nice day.
View 4 Replies
View Related
Feb 23, 2006
my table :
CREATE TABLE [dbo].[users] (
[ID] [int] NOT NULL ,
[A1] [nvarchar] (100) NULL ,
[A2] [nvarchar] (100) NULL ,
[A3] [nvarchar] (100) NULL
) ON [PRIMARY]
i must keep ID columns as primary key
ALTER TABLE [dbo].[users] WITH NOCHECK ADD
CONSTRAINT [PK_users] PRIMARY KEY CLUSTERED
(
[ID]
) ON [PRIMARY]
but now A1+A2 must be unique
how can i do it ?
thank you
View 5 Replies
View Related
May 15, 2008
hi guys,
i have 3 tables (T1, T2, T3), each with the same structure:
ID1 -> char(10)
ID2 -> char(12) NULL
ID3 -> char(10)
Value1 -> money
Value2 -> money
Value3 -> money
Note1 -> Text
Note2 -> Text
ID1+ID2+ID3 is the clusterd unique key in each table
what i want:
ID1, ID2, ID3 (with distinct occurencies of all 3 tables), T1.Value2, T2.Value2, T2.Value3, T3.Value1, T3.Note1
what i tried is to get all possible rows with
SELECT ID1,ID2,ID3 FROM T1
UNION
SELECT ID1,ID2,ID3 FROM T2
UNION
SELECT ID1,ID2,ID3 FROM T3
but i dont know how to join or add the other columns. maybe with
WITH RowList (ID1,ID2,ID3) AS ( ... code above.... ) SELECT ...
any ideas?
thx
View 10 Replies
View Related
Oct 31, 2005
Can you create a unique constraint on multiple columns, or does it haveto be implemented as a unique index?If possible can someone please post some sample code?Thanks,
View 4 Replies
View Related
Jul 20, 2005
Hi,I would like to add a unique index that consists of two fields in atable.e.g. tbl_A (field1,field2) -- field1 & field2 Indexed and combinationmust be Unique.Can anyone tell me the actual sql syntax to create this index?Thanks,June.
View 3 Replies
View Related
Feb 9, 2007
Perhaps one too many 2000 DTS packages have permanently damaged my ability to think clearly - however, I've find myself very frustrated attempting to create a SSIS Data Flow which replaces a very simple 2000 DTS package.
Take data from table1 in database1, put it in table2 in database2. Table2 in Database2 has an additional column as part of the primary key - so I need to add an arbitrary unique value in each row as it's inserted. Previously, I did this in the transformation script through a variable I incremented.
What's the recommend method to do this now - since row level processing of variables seem to be a no-no?
View 5 Replies
View Related
Aug 14, 2006
We have an app that threads together emails coming out of Exchange, using their messageid. To ensure threading works correctly, we need to ensure uniqueness of messageid, which we do with a unique index (we also need to be able to lookup by messageid when a message comes in).
We are currently porting the app from Oracle and PostgreSQL to SQL Server and are having problems with the 900 byte max length of an index. The problem is that the maximum size of a messageid (according to the Exchange docs) is 1877 bytes.
How can we guarantee uniqueness?
View 7 Replies
View Related
Mar 18, 2007
Hi there, im still learning SQL so thanks in advance.I have a table with columns of customer's information, [customerID], [customerFirst], [customerLast], , [program] ... other columns ... There will be entries where there can be duplicate customerFirst and customerLast names. I would like to just return a single entry of the duplicate names and all associated row information. IE: [customerID], [customerFirst], [customerLast], [ email], [program] 01 Bill Smith bill.smith@hotmail.com ymca 02 Bill Smith bill.smith@hotmail.com Sports 03 jon doe jon.doe@hotmail.com AAA 04 jon doe jon.doe@hotmail.com Ebay 05 Paul Sprite paul.sprite@hotmail.com Rec Desired Returned result: 01 Bill Smith bill.smith@hotmail.com ymca 03 jon doe jon.doe@hotmail.com AAA
05 Paul Sprite paul.sprite@hotmail.com Rec So in my code i have this:dAdapter = new SqlDataAdapter("SELECT * FROM [Poc_" + suffix + "] WHERE (SELECT DISTINCT [CustomerLastName], [CustomerFirstName], [CustomerEmail] FROM [Poc_" + suffix + "])", cnStr); dAdapter.Fill(pocDS, "Data Set"); However this is throwing up an error when i build the app: An expression of non-boolean type specified in a context where a condition is expected, near ')'.
Description: An
unhandled exception occurred during the execution of the current web
request. Please review the stack trace for more information about the
error and where it originated in the code.
Exception Details: System.Data.SqlClient.SqlException:
An expression of non-boolean type specified in a context where a
condition is expected, near ')'.
Source Error:
Line 52: //dAdapter = new SqlDataAdapter("SELECT DISTINCT * FROM [Poc_" + suffix + "] ORDER BY [CustomerLastName]", cnStr); Line 53: dAdapter = new SqlDataAdapter("SELECT * FROM [Poc_" + suffix + "] WHERE (SELECT DISTINCT [CustomerLastName], [CustomerFirstName], [CustomerEmail] FROM [Poc_" + suffix + "])", cnStr); Line 54: dAdapter.Fill(pocDS, "Data Set");Line 55: Line 56: //Dataset for name comparison 1: Can someone explain to me why this error is happening?2: Can soemone confirm that my intentions are correct with my code?3: If I'm completely off, can someone steer me in the right direction?Thanks alot!-Terry
View 12 Replies
View Related
Jan 19, 2008
Hello, I will explain myself further. I want to make my table in such a way that no two colums have the same value for example:
Row 1 - Column 1 = "cool"
Row 1 - Column 3 = 91
Row 3 - Column 1 = "cool"
Row 3 - Column 3 = 91
I dont care about one column having duplicate values, I want to protect against Column 1 and 3 having the same values on other rows. Is this possible to do in sql server?
View 4 Replies
View Related
Apr 3, 2000
I have 4 rows which are exactly the same. I want to delete one row but i do not have any unique identifing columns. How should i delete that row ?
View 1 Replies
View Related
Dec 30, 2004
I try to search my data and sort the result by importance.
I'm using a MS Access database and my data (table1) looks like this:
Code:
ID NAME TEXT
1 Apples Good red apples
2 Bananas Fine yellow bananas
3 Yellow apples Great yellow apples
I want to search the data and get a result where the column "NAME" is more important than "TEXT". My SQL looks like this:
Code:
SELECT id,name,text,1 AS searchorder FROM table1 WHERE name LIKE '*yellow*'
UNION
SELECT id,name,text,2 AS searchorder FROM table1 WHERE text LIKE '*yellow*'
ORDER BY searchorder
The output is this:
Code:
ID NAME TEXT SEARCHORDER
3 Yellow apples Great yellow apples 1
2 Bananas Fine yellow bananas 2
3 Yellow apples Great yellow apples 2
So far so good - the order by importance works - but I do not get unique columns because of the searchorder column.
Can I fix my SQL so I get unique columns where the last line of "Yellow apples" does not appear or am I lost in space?
Best regards,
Peter from Denmark
View 2 Replies
View Related
Jun 20, 2008
Hi Guys.
I have a problem. I have two feilds in a table. Both of them are (int). I want to be able make sure the same number is not put in both columns for each row. Both colums have to be a different number, and also if one is null, the other cannot be. How do I go about enforcing this policy?
For Example:
This is what I want
ID Column1 Column2
--- -------- ---------
1 5 8
2 5 7
3 null 10
4 6 2
This is what I DO NOT want:
ID Column1 Column2
--- -------- ---------
1 5 5
2 5 5
3 7 7
4 null null
I created a unique constraint between the 2 columns, but it still allows dups within the row. Please help me.
View 1 Replies
View Related
May 5, 2008
I am trying to create a Unique Constraint on a SQL Server 2005 table where the uniqueness is based on 2 columns.
Could anybody provided some help on how I could enforce this on an existing table (link, or example) I have been looking around without luck.
Thanks in advance
John.
View 4 Replies
View Related
Apr 18, 2014
write a query which retrieves only unique rows excluding some columns.
IdStatusmanager Team Comments Proj number Date
19391New XUnassigned One 3732.0 16-Apr-14
19392Can YCustomer Two 3732.0 17-Apr-14
19393Can YCustomer Two 3732.0 17-Apr-14
19394Can YCustomer One 3732.0 18-Apr-14
19395New YCustomer One 3732.0 19-Apr-14
19396New YCustomer One 3732.0 21-Apr-14
19397New ZCustomer One 3732.0 20-Apr-14
In the above table project number and id shouldn't be considered and I should get the unique rows considering rest of columns and sorted based on date. Expected result is
IdStatusmanager Team Comments Proj number Date
19391New XUnassigned One 3732.0 16-Apr-14
19392Can YCustomer Two 3732.0 17-Apr-14
19394Can YCustomer One 3732.0 18-Apr-14
19395New YCustomer One 3732.0 19-Apr-14
19397New ZCustomer One 3732.0 20-Apr-14
19396New YCustomer One 3732.0 21-Apr-14
View 4 Replies
View Related
Sep 19, 2006
andre writes "I have two questions:
1.)How do i determine if fields are not unique??
2) How to update one table with values from another table when the row names are diffrent??
Thank you!!"
View 1 Replies
View Related
Oct 19, 2015
I am trying to achieve the below problem statement, however I am getting stuck at the looping part.
EX: We have three columns
First Name | Last Name | Mothers Name
I want to generate the username field using above columns, so lets consider, I have following data
First Name | Last Name | Mothers Name
a b cdef
a b cdfg
a b cdfj
Expected Usernames:
1: a.b
2: a.b.c
3. a.b.cd
Basically, it has to be FirstName.LastName.(incremental letters from MothersName until the name becomes unique)
View 4 Replies
View Related
May 11, 2015
I would like to know what is the use of business key? Is it necessary to have unique key between source and destination? If no, How can we implement SCD?
PS : My source is CSV files and Destination is Oracle DB?
View 2 Replies
View Related
Sep 15, 2014
I am looking to create a script that will go through a table a pick out the necessary columns to create a unique record. Some of the tables that I am working with have 200 plus columns and I am not sure if I would have to list every column name in the script or if they could be dynamically referenced. I am working with a SQL server that has little next to no documentation and everytime I type to mere some tables, I get too many rows back.
View 4 Replies
View Related
Oct 27, 2015
We are on SQL 2014...we have a bunch of views in a database where we are trying to find the views which have more than 16 columns max for unique index/constraint...this is needed so we can convert them to indexed views...
View 1 Replies
View Related
Sep 16, 2015
In SQL 2012.A query that joins 2 table, with order by clause doesn't get sorted and the result set is not ordered. This happens when some of the columns in the where criteria are in a unique index which is the index that is used for the join between the 2 tables, and all the columns in the unique index are in the where criteria.In the query plan there is no component for sort.The work around was to drop the unique index, or change it to a non-unique index. Once this was done, the execution plan was changed to add the sort component (even when the index was changed to non-unique and the join was still using this index).
View 4 Replies
View Related
Jul 5, 2015
This index is not unique
ix_report_history_creative_id
Msg 2601, Level 14, State 1, Procedure DFP_report_load, Line 161
Cannot insert duplicate key row in object 'dbo.DFP_Reports_History' with unique index 'ix_report_history_creative_id'.
The duplicate key value is (40736326382, 1, 2015-07-03, 67618862, 355324).
Msg 3621, Level 0, State 0, Procedure DFP_report_load, Line 161
The statement has been terminated.
Exception in Task: Cannot insert duplicate key row in object 'dbo.DFP_Reports_History' with unique index 'ix_report_history_creative_id'. The duplicate key value is (40736326382, 1, 2015-07-03, 67618862, 355324).
The statement has been terminated.
View 6 Replies
View Related
Nov 6, 2007
Hi all,
I have a table in xyz database and there is no column in table like creation_date or modified_date.
The problem is I want to delete records which has been added in the table before 1st jan 2007.
The size of table is 85 GB
Immediate help would be appriciable.
Regards,
Frozen
View 9 Replies
View Related
Sep 22, 2004
A UNIQUE INDEX must inherently impose a unique constraint and a UNIQUE CONSTRAINT is most likely implemented via a UNIQUE INDEX. So what is the difference? When you create in Enterprise Manager you must select one or the other.
View 8 Replies
View Related
Jul 20, 2005
HelloWhat should I use for better perfomance sinceunique constraint always use index ?ThanksKamil
View 5 Replies
View Related
