ALTER TABLE Log ADD log_id bigint IDENTITY BEFORE cust_id_fk
The above code adds a new column to last position. I want it to be added to the first position. Also I want to make it as Primary Key.
You would need to drop the table and recreate it with the columns in the correct order. If you make the table changes in SSMS then it can generate a change script for you which you could then use to deploy the change to a production server.
Even if the question is old, a more accurate about Management Studio would be required.
You can create the column manually or with Management Studio. But Management Studio will require to recreate the table and will result in a time out if you have too much data in it already, avoid unless the table is light.
To change the order of the columns you simply need to move them around in Management Studio. This should not require (Exceptions most likely exists) that Management Studio to recreate the table since it most likely change the ordination of the columns in the table definitions.
I've done it this way on numerous occasion with tables that I could not add columns with the GUI because of the data in them. Then moved the columns around with the GUI of Management Studio and simply saved them.
You will go from an assured time out to a few seconds of waiting.
In MSSMS select the table in the object explorer. Right click and select modify.
That will bring a new tab where you can drag the columns into a new default order.
Save and presto! Done.
Steps:
Rename the original table to tablename_temp
create a new table containing the new column
insert into tablename select * from tablename_temp
recreate foreign keys and other constraint on the new table
Short answer: It's not possible.
But you may try these steps:
Right click table name on object explorer
Click tasks
Click drop and create table
Add your columns in the position you want to add them
If you have data. Copy the data and paste it on an Excel spreadsheet, edit the spreadsheet to include new columns,edit top 100 rows and paste the data back into the table.
Goodluck
According to Change Column Order in a Table, this operation is not supported using the Transact-SQL statement.
You have to create another table and copy the data. But have a look at "ordinal position" and try to update it ?
SELECT
ORDINAL_POSITION
,COLUMN_NAME
,DATA_TYPE
,CHARACTER_MAXIMUM_LENGTH
,IS_NULLABLE
,COLUMN_DEFAULT
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME = 'Product'
ORDER BY
ORDINAL_POSITION ASC;
Primary key is another question for which you may find lots of answers.
Related
I need to make a provisionary table (TAB_PROV). This table will have its origin in a main table (TAB_MAIN). I need everything from the main table, except the data (rows).
I searched for some examples and none of them worked for me
CREATE TABLE TAB_PROV LIKE TAB_MAIN
CREATE TABLE TAB_PROV AS TAB_MAIN
You can just simply do:
SELECT *
FROM TAB_MAIN
INTO TAB_PROV
WHERE 1 = 2
Since the WHERE condition will never be true, no data is ever copied - but the table structure is replicated - TAB_PROV is created and has the same column as TAB_MAIN. This does NOT however copy any constraints (check or default constraints) or triggers over - it only recreates the columns (and their datatypes).
If you want a real and complete "copy" of your table, then you should use the "Script Table" function in SSMS to get the SQL needed for TAB_MAIN and then adapt it to create TAB_PROV from it.
In SQL Server Management Studio, you can right-click the table and select
Script Table as -> Create To -> New Query Editor Window
This will create just the table creation script for you.
You can also try the code below but it will copy everything.
SELECT *
INTO NewTable
FROM OldTable
TRUNCATE TABLE NewTable
I have situation where I need to change the order of the columns/adding new columns for existing Table in SQL Server 2008.
Existing column
MemberName
MemberAddress
Member_ID(pk)
and I want this order
Member_ID(pk)
MemberName
MemberAddress
I got the answer for the same ,
Go on SQL Server → Tools → Options → Designers → Table and Database Designers and unselect Prevent saving changes that require table re-creation
2- Open table design view and that scroll your column up and down and save your changes.
It is not possible with ALTER statement. If you wish to have the columns in a specific order, you will have to create a newtable, use INSERT INTO newtable (col-x,col-a,col-b) SELECT col-x,col-a,col-b FROM oldtable to transfer the data from the oldtable to the newtable, delete the oldtable and rename the newtable to the oldtable name.
This is not necessarily recommended because it does not matter which order the columns are in the database table. When you use a SELECT statement, you can name the columns and have them returned to you in the order that you desire.
If your table doesn't have any records you can just drop then create your table.
If it has records you can do it using your SQL Server Management Studio.
Just click your table > right click > click Design then you can now arrange the order of the columns by dragging the fields on the order that you want then click save.
Best Regards
I tried this and dont see any way of doing it.
here is my approach for it.
Right click on table and Script table for Create and have this on
one of the SQL Query window,
EXEC sp_rename 'Employee', 'Employee1' -- Original table name is Employee
Execute the Employee create script, make sure you arrange the columns in the way you need.
INSERT INTO TABLE2 SELECT * FROM TABLE1.
-- Insert into Employee select Name, Company from Employee1
DROP table Employee1.
Relying on column order is generally a bad idea in SQL. SQL is based on Relational theory where order is never guaranteed - by design. You should treat all your columns and rows as having no order and then change your queries to provide the correct results:
For Columns:
Try not to use SELECT *, but instead specify the order of columns in the select list as in: SELECT Member_ID, MemberName, MemberAddress from TableName. This will guarantee order and will ease maintenance if columns get added.
For Rows:
Row order in your result set is only guaranteed if you specify the ORDER BY clause.
If no ORDER BY clause is specified the result set may differ as the Query Plan might differ or the database pages might have changed.
Hope this helps...
This can be an issue when using Source Control and automated deployments to a shared development environment. Where I work we have a very large sample DB on our development tier to work with (a subset of our production data).
Recently I did some work to remove one column from a table and then add some extra ones on the end. I then had to undo my column removal so I re-added it on the end which means the table and all references are correct in the environment but the Source Control automated deployment will no longer work because it complains about the table definition changing.
The real problem here is that the table + indexes are ~120GB and the environment only has ~60GB free so I'll need to either:
a) Rename the existing columns which are in the wrong order, add new columns in the right order, update the data then drop the old columns
OR
b) Rename the table, create a new table with the correct order, insert to the new table from the old and delete from the old as I go along
The SSMS/TFS Schema compare option of using a temp table won't work because there isn't enough room on disc to do it.
I'm not trying to say this is the best way to go about things or that column order really matters, just that I have a scenario where it is an issue and I'm sharing the options I've thought of to fix the issue
SQL query to change the id column into first:
ALTER TABLE `student` CHANGE `id` `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT FIRST;
or by using:
ALTER TABLE `student` CHANGE `id` `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT AFTER 'column_name'
Not sure if this is even allowed, but if so, can someone tell me what the T-SQL is? I've tried the following but to no avail.
alter [View_Name]
alter column [Coln_Name] [New size/length] not null
GO
Any help is appreciated. Thanks!
Not directly.
This is derived automatically from the column expression. You can CAST the expression in the View SELECT list to a particular datatype though.
You would need to change the column length in the underlying table, or to change the SELECT statement forming the view to CAST or CONVERT the column to a different length data type.
Views are ways to see data in other tables; typically the data is simply whatever is in the underlying table, so you would need to change the column there.
However, you can have views that do things like cast() or convert(); these are typically a bad idea, becuase the data needs to be re-fetched every time the view is used, and these operations add overhead. In the design of the view, you can decide to cast as another data type, or do any transformation you would like - but it has overhead, and will not alter the original data.
If you know what the current view selects, you can use something like:
Alter view Viewname[cloumn] as Select cast(original_data as varchar(n)) from Original_Table
I just ran into the same situation. What I did was:
Change the column size in the table that the view looks at.
Create a script to recreate the view (if you don't already have one).
Delete the view
Use the script to recreate the view.
After that the column sizes in the view were the same as the changes I made to the underlying table.
You can not alter the column size in a view as a view is derived from other table. So if you need to change the column size, change the column size of the table. To change the column size use ALTER TABLE as :
ALTER TABLE [Table_Name]
ALTER COLUMN [Column_Name] Data_Type(Size)
After changing the column size you might need to drop the view and recreate it again.
If the length shown in the view doesn't match the underlying table then drop and recreate the view.
Use something like this to investigate the column lengths in the table and view
SELECT o.[name], *
FROM sys.all_columns c
INNER JOIN sys.objects o on o.[object_id]=c.[object_id]
WHERE c.[name] = 'OML'
-- AND c.[max_length]=11
ORDER BY O.[name];
To get the Drop and Create sql I use SSMS and right click context menu (on the view in the Object Explorer), then go to 'Script View as', and 'DROP And CREATE To'.
Is there a way to find out the data a row has been inserted (into a SQL Server 2005, 2008 or 2008 r2) database table? Without setting up auditing (either ootb or custom 3rd party product).
Thanks
You can always create a trigger on that table. Like so:
create trigger InsertNotification
on YourTable
after insert
as
-- do whatever you want when an insert happens
go
This can definitely be seen as a form of "auditing", but I'm not familiar with "ootb", nor is this a 3rd party product. Triggers are the way to go.
Well if you want to be notified when the row is inserted make insert trigger to this table.
If you just want to save the information when a specific row was inserted, you could just create a new datetime or smalldatetime column with getdate() as the default value.
Whenever a new row is inserted, this column will be automatically filled with the current date/time.
Advantages:
no trigger or 3rd party tool needed
Disadvantages:
this only works for new tables (or all new records in existing tables). If a table already has existing records, you won't have an insert date/time for them
if you want this for all your tables, you have to insert the column into each table
I would like to have a column in my DB accessible via two column names temporarily.
Why? The column name was badly chosen, I would like to refactor it. As I want my webapp to remain stable while changing the column name, it would be good to
have a (let's call it) symlink named better_column_name pointing to the column bad_column_name
change the webapplication to use better_column_name
drop the symlink and rename column to better_column_name
"Refactoring Databases" suggests to actually add a second column which is synchronized on commit in order to achieve this. I am just hoping that there might be an easier way with Oracle, with less work and less overhead.
As long as you have code that uses both column names, I don't see a way to get around the fact that you'll have two (real) columns in that table.
I would add the new column with the correct name and then create a trigger that checks which column has been modified and updates the "other" column correspondingly. So whatever is being updated, the value is synch'ed with the other column.
Once all the code that uses the old column has been migrated, remove the trigger and drop the old column.
Edit
The trigger would so do something like this:
CREATE OR REPLACE TRIGGER ...
...
UPDATE OF bad_column_name, better_column_name ON the_table
...
BEGIN
IF UPDATING ('BAD_COLUMN_NAME') THEN
:new.better_column_name = :new.bad_column_name
END IF;
IF UPDATING ('BETTER_COLUMN_NAME') THEN
:new.bad_column_name = :new.better_column_name
END IF;
END;
The order of the IF statements controls which change has a "higher priority" in case someone updated both columns at the same time.
Rename the table:
alter table mytable rename to mytable_old;
Create a view with the original tablename with both bad_column_name and better_column_name that point to the same column (and of course all the other columns):
create or replace view mytable as
select column1
, column2
, ...
, bad_column_name
, bad_column_name better_column_name
from mytable_old
;
Since this view is updatable by default (I assume here that mytable has a primary key), you can insert/update/delete from the view and it doesn't matter if you use bad_column_name or better_column_name.
After the refactoring, drop the view and rename the table and column:
drop view mytable;
alter table mytable_old rename column bad_column_name to better_column_name;
alter table mytable_old rename to mytable;
The best solution to this is only available in Oracle 11g Release 2: Edition-based Redefinition. This really cool feature allows us to maintain different versions of database tables and PL/SQL code, using special triggers and views. Find out more.
Essentially this is Oracle's built-in implementation of #AHorseWithNoName's suggestion.
you can create a view for the table. And port your application to use that view instead of the table.
create table t (bad_name varchar2(10), c2 varchar2(10));
create view vt as select bad_name AS good_name, c2 from t;
insert into vt (good_name, c2) values ('blub', 'blob');
select * from t;
select * from vt;
If you're on 11g you could look at using a virtual column. I'd probably be tempted to change the order slightly; rename the real column and create the virtual one using the old (bad) name, which can then be dropped at leisure. You may be restricted, of course, and there may be implications on other objects being invalidated that make this order less suitable for you.