When doing merge replication, is the column ROWGUIDCOL compulsory? Can I use a custom column I have created that will be unique across all databases?
Does this mean I have to use GUID as my primary key or can i have a gUID column and my custom id column as well?
When I try to create a merge replication, it wants to add a guid column and I am not sure if thats what i want to do.
Any suggest a stragety to create a merge replication? I really want to avoid using a guid as my primary key on all tables...this would also create a alot of work for our application
Per Considerations for Merge Replication, each published table requires a GUID column with the ROWGUIDCOL property set and a unique index.
Merge replication uses a globally unique identifier (GUID) column to
identify each row during the merge replication process. If a published
table does not have a uniqueidentifier column with the ROWGUIDCOL
property and a unique index, replication adds one. Ensure that any
SELECT and INSERT statements that reference published tables use
column lists. If a table is no longer published and replication added
the column, the column is removed; if the column already existed, it
is not removed.
Related
I am trying to change a primary key Id to identity to increment 1 on each entry. But the column has been referenced already by other tables. Is there any way to set primary key to auto increment without dropping the foreign keys from other tables?
If the table isn't that large generate script to create an identical table but change the schema it created to:
CREATE TABLE MYTABLE_NEW (
PK INT PRIMARY KEY IDENTITY(1,1),
COL1 TYPEx,
COL2 TYPEx,
COLn
...)
Set your database to single-user mode or make sure no one is in the
database or tables you're changing or change the table you need to
change to READ/ONLY.
Import your data into MYTABLE_NEW from MYTABLE using set IDENTITY_INSERT on
Script your foreign key constraints and save them--in case you need
to back out of your change later and/or re-implement them.
Drop all the constraints from MYTABLE
Rename MYTABLE to MYTABLE_SAV
Rename MYTABLE_NEW to MYTABLE
Run constraint scripts to re-implement constraints on MYTABLE
p.s.
you did ask if there was a way to not drop the foreign key constraints. Here's something to try on your test system. on Step 4 run
ALTER TABLE MYTABLE NOCHECK CONSTRAINT ALL
and on Step 7 ALTER TABLE MYTABLE CHECK CONSTRAINT ALL. I've not tried this myself -- interesting to see if this would actually work on renamed tables.
You can script all this ahead of time on a test SQL Server or even a copy of the database staged on a production server--to make implementation day a no-brainer and gauge your SLAs for any change control procedures for your company.
You can do a similar methodology by deleting the primary key and re-adding it back, but you'll need to have the same data inserted in the new column before you delete the old column. So you'll be deleting and inserting schema and inserting primary key data with this approach. I like to avoid touching a production table if at all possible and having MYTABLE_SAV around in case "anything" unexpected occurs is a comfort to me personally--as I can tell management "the production data was not touched". But some tables are simply too large for this approach to be worthwhile and, also, tastes and methodologies differ largely from DBA to DBA.
I am using SQL Server 2012 and need to add a column with a unique primary key. I am about to load several hundred thousand records BULK and just discovered repetition in the field I was going to use. Have seen SEQUENCE and GUID. Need some guidance on the best choice and how to go about setting this up so that the key field is populated during the bulk load.
When you create your table in which you want to insert information create an IDENTITY column. That will serve as an auto-populating column with a unique number for each record.
Here is a link that might help you.
If you have already created your table just change this query to what suits to your table name and run it in order to add the new column you requested.
ALTER TABLE mytable
ADD COLUMN unique_id IDENTITY (1,1)
Just a slight update on what’s already posted that includes details for adding primary key constraint
alter table database.schema.table_t
add ID_column int identity(1,1)
primary key (ID_column)
If you already set the primary key on this table just go and remove it before you execute this statement.
In my application, using SQL Server 2005, I'm having two tables, let's call them Table A and Table B; a foreign key constraint is defined on Table B, referencing the primary-key column in Table A, which is an auto-generated integer ID. I'm running the following simple transaction:
Start transaction
Insert a row to table A
Retrieve the last-generated ID ("SELECT ##IDENTITY ... ")
Insert data to table B, using this ID
Commit
It all works well, until I'm trying to create merge replication (continuous) with another SQL Server 2005. Both publisher and subscriber now fail this transaction when trying to insert data to table B, because of foreign key constraint failure:
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_TableB_TableA". The conflict occurred in database "MyDB", table "TableA", column 'ID'.
I was not able to make it work by committing after inserting data to table A. However, after removing the merge replication, everything worked. The database code is written in C++, using ADO.
Is the replication interfering with the transaction anyhow? Any other possible explanation?
Are the Primary Key values on Table A at both server nodes discrete from one another (In other words are you using Identity Range management at each node)?
Also, has the Foreign Key constraint been configured with the Not For Replication property?
I would assume that because your Foreign Key constraint has already been enforced locally at the Publisher, that you do not need to re-check it when merging with the Subscriber.
Looks like the issue is related to the scope of the ##IDENTITY function. When I used LAST_IDENT('TableB') instead, things seem to work.
As described in MSDN:
IDENT_CURRENT returns the last identity value generated for a specific table in any session and any scope.
##IDENTITY returns the last identity value generated for any table in the current session, across all scopes.
SCOPE_IDENTITY returns the last identity value generated for any table in the current session and the current scope.
using replication in sql srv causes the addition of this guid field, it also adds a value to it
but when i insert new records to the db, i have to give somthing or the guid field
it should be like aaaaa-aaa-something and unique!!
this is a problem for me , how am i supposed to do this keeping it unique every time?
should sql srv automatically add some yhing?
The ROWGUIDCOL added by Merge Replication should be populated with... guids:
ROWGUIDCOL does not enforce uniqueness
of the values that are stored in the
column and does not automatically
generate values for new rows that are
inserted into the table. To generate
unique values for each column, either
use the NEWID function on INSERT
statements or specify the NEWID
function as the default for the
column.
I have a SQL Server database with an Apartment table (which has columns FloorNum and BuildingID) and an ApartmentBuilding table (with column NumFloors). Is there any way to set up a constraint (using the SQL Server UI) to check that Apartment.FloorNum is greater than ApartmentBuilding.NumFloors?
I tried this:
FloorNum > ApartmentBuilding.NumFloors
but now I realize that I somehow have to join the columns on the BuildingID, but I have no idea how to do that within a constraint.
Thanks for your help!
You can't do this with a CHECK CONSTRAINT since it requires data from another table. You would handle this with an INSERT/UPDATE trigger.
In ApartmentBuilding table, add UNIQUE constraint on(BuildingID, NumFloors)
In Apartment table, add column NumFloorsInBuilding
In Apartment table, add foreign key on (BuildingID, NumFloorsInBuilding) referring to (BuildingID, NumFloors). This guarantees that NumFloorsInBuilding is always equal to NumFloors in parent table.
In Apartment table, add CHECK(FloorNum < NumFloorsInBuilding)