Whenever I want to add a column to a table it usually goes something like this:
Fire up SQL Server Management Studio (SSMS)
Select "Design" on the table I want to add the column to
Add the new column to the table
Save
Get an error that SSMS can't save because it would need to drop the table (and it can't because the the table has foreign keys on it).
Get frustrated that I forgot that this is something that SSMS can't do
Construct an alter table command by hand to add the column
Move on with life.
This time I am adding a step between numbers 6 and 7. I thought I would ask why SSMS can't make a simple alter table statement to add my new column in.
(In case it matters I am running SSMS 2008 against SQL Server 2008.)
Alternatively, you can go to Tools-->Options-->Designers-->Table and Database Designers and uncheck "Prevent saving changes that require table re-creation"
Problem solved.
Here's an explanation from MSDN: http://support.microsoft.com/default.aspx/kb/956176.
When you change a table so that you
alter the metadata structure of the
table, and then you save the table,
the table must be re-created based on
these changes.
Related
I have sql Upgrade script which has many sql statements(DDL,DML). When i ran this upgrade script in SQL developer, it runs successufully.I also provide in my script at the bottom commit. I can see all the changes in the database after running this upgrade script except the unique index constraints. When i insert few duplicate records it says unique constraint violated. It means the table has unique constraints. But i dont know why i cant view this constraints in oracle sql developer. The other DDL changes made i can view.I dont know is there any settings to view it in oracle sql developer.
CREATE UNIQUE INDEX "RATOR_MONITORING"."CAPTURING_UK1" ON "RATOR_MONITORING"."CAPTURING" ("DB_TABLE");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND" ("NAME");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_BUSINESS_PROCESS_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND_BUSINESS_PROCESS" ("BRAND_ID", "BP_ID");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_ENGINE_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND_ENGINE" ("BRAND_ID", "ENGINE_ID");
As A Hocevar noted, if you create an index
create unique index test_ux on test(id);
you see it in the Indexes tab of the table properties (not in the Constraints tab).
Please note that COMMIT is not required here, it is done implicitely in each DDL statement. More usual source of problems are stale metadata in SQL Developer, i.e. missing REFRESH (ctrl R on user or table node).
If you want to define the constraint, add following statement, that will reuse the index defined previously
alter table test add constraint test_unique unique(id) using index test_ux;
See further discussion about the option in Documentation
I am assuming you are trying to look for index on a table in the correct tab in sql developer. If you are not able to see the index there, one reason could be that your user (the one with which you are logged in) doesn't have proper rights to see the Index.
If you not obtain any error, the solution is very simple and tedious. SQL Developer doesn't refresh his fetched structures. Kindly push Refresh blue icon (or use Ctrl-R) in Connections view or disconnect and connect again (or restart SQL Developer) to see your changes in structures.
I know you can go into the design view of a table in SQL Server Management Studios and reorder columns as they appear in the design view, however this isn't possible with SQL Azure as the option is disabled. Is there a way to modify SQL Azure tables so that you can reorder their columns as they appear in the design view?
I have been running a number of database upgrades over the last few months to support new requirements and would like to reorder the way the columns appear in design view so they're easier to read, i.e. so they start with a primary key, followed by foreign keys, then normal columns and end with the added by, modified by fields. Its purely to make the tables more readable as I manage them over time.
Just run a script against the table. Its a bit of pseudocode but you should get the idea.
CREATE TABLE TableWithDesiredOrder(PK,FK1,FK2,COL1,COL2)
INSERT INTO TableWithDesiredOrder(PK,FK1,FK2,COL1,COL2....)
SELECT PK,FK1,FK2,COL1,COL2.... FROM OriginalTable
DROP TABLE OriginalTable
Finally Rename the table
sp_Rename TableWithDesiredOrder, OriginalTable
Just another option: I use SQL Delta to propagate my db changes from dev db up to Azure db. So in this case, I just change the col order locally using SSMS GUI, and SQL Delta will do the createnew>copytonew>dropold for me, along with my other local changes. (In Project Options, I set Preserve Column Order=Yes.)
I experienced the same with Azure SQL Database, basically my view changes with ALTER were not taken when did a SELECT * from the view, or the column headers were mixed with the column values.
In order to fix it I dropped the view and re-created it again. That worked.
On our original design we screwed up a foreign key constraint in our table. Now that the table is full of data we cannot change it without dropping all of the records in the table. The only solution I could think of is to create a backup table and put all of the records in there, then delete all the records, alter the table and start adding them back. Any other (BETTER) ideas? Thanks!
Using MS SQL Server
I'm a bit late, just for reference.
If You are using SQL Server Management Studio, You could generate a DROP and RECREATE script with "Keep schema and data" option.
Right click on the desired DB in object explorer
Tasks > Generate scripts
Select the table you want to script
Then clicking on Advanced button
"Script DROP and CREATE" ->"Script DROP and CREATE"
"Types of data to script" -> "Schema and data"
Hope this helps
Here's some pseudo-code. No need to make a backup table, just make a new table with the right constraint, insert your records into it, and rename.
CREATE TABLE MyTable_2
(...field definitions)
<add the constraint to MyTable_2>
INSERT INTO MyTable_2 (fields)
SELECT fields
FROM MyTable
DROP TABLE MyTable
exec sp_rename 'MyTable2', 'Mytable'
Using SQL Server Management Studio (SSMS), you can use it's table designer to specify the final condition of the table. Before saving the changes, have it generate the change script and save that script. Cancel out of the design window, open the script and review it. SSMS may already have generated a script that does everything you need, fixing the primary-foreign key relationship while preserving all existing data. If not, you will have a script, already started, that performs most of what you need to do and should be able to modify it for your needs.
This is your only solution.
Create the backup table, empty the original one, modify the table and then insert step-by-step until you find a violation.
Update All Schema Database Old by new Schema Database .
Create script (Right click on the desired DB in object explorer Tasks > Generate scripts -> select option select specific database objects and tables ->next -> advanced-> option Type of data to script Data only -> ok ->next ->next.) to data only and backup Database to old database
Drop database old and create new database and make new DB is empty .
Excute script of Old Data only on new database .
sometimes i face the following case in my database design,, i wanna to know what is the best practice to handle this case:::
for example i have a specific table and after a while ,, when the database in operation and some real data are already entered.. i need to add some required fields (that supposed not to accept null)..
what is the best practice in this situation..
make the field accept null as (some data already entered in the table ,, and scarify the important constraint )and try to force the user to enter this field through some validation in the code..
truncate all the entered data and reentered them again (tedious work)..
any other suggestions about this issue...
It depends on requirements. If the data to populate existing rows for the new column isn't available immediately then I would generally prefer to create a new table and just populate new rows when the data exists. If and when you have all the data for every row then put the new column into the original table.
If possible i would set a default value for the new column.
e.g. For Varchar
alter table table_name
add column_name varchar(10) not null
constraint column_name_default default ('Test')
After you have updated you could then drop the default
alter table table_name
drop constraint column_name_default
A lot will come down to your requirements.
It depends on your application, your database scheme, your entities.
The best way to go about it is to truncate the data and re - enter it again, but it need not be too tedious an item. Temporary tables and table variables could assist a great deal with this issue. A simple procedure comes to mind to go about it:
In SQL Server Management Studio, Right - click on the table you wish to modify and select Script Table As > CREATE To > New Query Editor Window.
Add a # in front of the table name in the CREATE statement.
Move all records into the temporary table, using something to the effect of:
INSERT INTO #temp SELECT * FROM original
Then run the script to keep all your records into the temporary table.
Truncate your original table, and make any changes necessary.
Right - click on the table and select Script Table As > INSERT To > Clipboard, paste it into your query editor window and modify it to read records from the temporary table, using INSERT .. SELECT.
That's it. Admittedly not quite straightforward, but a well - kept database is almost always worth a slight hassle.
I wanted to modify a column in a sql server 2005 table to IDENTITY(1,1)
Incidentally this table is empty and the column to be changed is a primary key.
This column is also a foreign key for two other tables.
After googling I found that you cannot use Alter table syntax to modify a column and make it an indentity column.
Link #1 : How do I add the identity property to an existing column in SQL Server
Link #2 : Adding an identity to an existing column -SQL Server
I ended up checking the dependent tables (2 of them) removing the foreign keys (generated the script from SSMS) then dropping the main table then re-creating with identity. (could try the rename option here as well)
Then re-created the foreign keys for the earlier dependent two tables.
But all this was manual work, any scripts or SPs out there to make this easier.
Ideally all these steps would be done by such a script/tool/utility:
Check dependent tables keys
Generate Create and drop foreign key scripts for this
Generate create script for the main table
drop the main table (or rename the table if the table has data)
re-create the table with identity column enabled
re-create foreign keys
You can use SSMS to generate a script (Edit a table, save script), but otherwise it's a manual process as you identified.
The SSMS scripts will pick up dependencies etc. For this kind of work, I tend to use SSMS to generate a basic script, pimp it a bit, run it carefully, then use a comparison tool (such as Red Gate compare) to generate a safer version.
Edit: The SSMS error is not an error, it's a safety check that can be switched off
(This is merely a follow-up to gbn's post with more details -- it isn't all that easy to figure this stuff out.)(
It isn't impossible to write a utility to do this, just very complex and very hard. Fortunately, Microsoft has already done it -- its called SSMS (or SMO?). To generate such a script:
In the Object Explorer, drill down to the database and table that you want to modify
Right click and select Design
Make the desired changes to the one table in the design screen. It's reasonably intuitive.
To add/remove the identity property, select the column in the upper pane, and in the lower pane/"Column Properties" tab, expand and configure the settings under "Identity Specification".
To generate a script to implement all your changes, incorporating all the dependent key changes, click on the "Generate Change Script" toolbar button. This is also an option under the "Table Designer" menu.
I also do this to generate scripts (that I later modify--SSMS doesn't always produce the most efficient code.) Once done, you can exit out without saving your changes -- leaving you a DB you can test your new script on.
drop the pk and build the same datatype column
copy the data of the column which you want to set identity to the new column.
drop the old column
reset primary key
ALTER TABLE UserRole
DROP CONSTRAINT PK_XX
ALTER TABLE XX
ADD newX int not null identity(1,1) primary key
update XX set newX = oldX
alter table XX
DROP COLUMN oldX
this is the simplest way to set identity column.
if you don't want to use the long generated script.