How To change the column order in sql server 2008 R2?
Eg: My table order is Eid------Ename-----Esalary
Know i want this format like Eid---Salary----Ename
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You shouldn't care about physical column order in the table. The only case where this should be a concern is if you're using
SELECT * - and you shouldn't be doing that, you should be listing the column names explicitly (and you can then put the columns in any order you want).
You can drop and re-create the table, like others have said, with the columns in your preferred order. But this is going to be very disruptive (blocking, I/O) if your table is large, since all of the other users on the system will have to wait for that to complete. If you want to see exactly what Management Studio does, create this table:
CREATE TABLE dbo.foo(b INT, a INT, r INT); INSERT dbo.foo(b,a,r) VALUES(1,2,3),(4,5,6);
Now, in Object Explorer, right-click the table and choose Design. Select the box to the left of the column name that you want to reorder. Drag the column to another location within the table. I moved
b because I'm OCD and wanted the columns in alphabetical order:
Then I clicked the "Generate Change Script" button, and here is the monstrosity that it created (and note this is a heap with no keys, constraints, triggers etc. - this re-create can get pretty complex).
/* To prevent any potential data loss issues, you should review this script in detail before running it outside the context of the database designer. */ BEGIN TRANSACTION SET QUOTED_IDENTIFIER ON SET ARITHABORT ON SET NUMERIC_ROUNDABORT OFF SET CONCAT_NULL_YIELDS_NULL ON SET ANSI_NULLS ON SET ANSI_PADDING ON SET ANSI_WARNINGS ON COMMIT BEGIN TRANSACTION GO CREATE TABLE dbo.Tmp_foo ( a int NULL, b int NULL, r int NULL ) ON [PRIMARY] GO ALTER TABLE dbo.Tmp_foo SET (LOCK_ESCALATION = TABLE) GO IF EXISTS(SELECT * FROM dbo.foo) EXEC('INSERT INTO dbo.Tmp_foo (a, b, r) SELECT a, b, r FROM dbo.foo WITH (HOLDLOCK TABLOCKX)') GO DROP TABLE dbo.foo GO EXECUTE sp_rename N'dbo.Tmp_foo', N'foo', 'OBJECT' GO COMMIT
For fun, let's create something a little more complex:
CREATE TABLE dbo.flarb ( a INT PRIMARY KEY, b INT NOT NULL CHECK (b>1), c ROWVERSION, d DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP, e UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID() ); CREATE TABLE dbo.blarf ( a INT NOT NULL FOREIGN KEY REFERENCES dbo.flarb(a) ); GO CREATE TRIGGER dbo.flarb_tr ON dbo.flarb FOR UPDATE AS SELECT 1; GO CREATE VIEW dbo.flarb_v WITH SCHEMABINDING AS SELECT a FROM dbo.flarb;
Now we try the same thing:
- Error validating the default for column 'e'.
- Warning: The following schema-bound objects will be modified:
- View 'dbo.flarb_v': schema binding will be removed.
Oops. Thankfully, we can still proceed to see what the script will look like:
/* To prevent any potential data loss issues, you should review this script in detail before running it outside the context of the database designer. */ BEGIN TRANSACTION SET QUOTED_IDENTIFIER ON SET ARITHABORT ON SET NUMERIC_ROUNDABORT OFF SET CONCAT_NULL_YIELDS_NULL ON SET ANSI_NULLS ON SET ANSI_PADDING ON SET ANSI_WARNINGS ON COMMIT BEGIN TRANSACTION GO ALTER VIEW dbo.flarb_v AS SELECT a FROM dbo.flarb;GO ALTER TABLE dbo.flarb DROP CONSTRAINT DF__flarb__d__1B7E091A GO ALTER TABLE dbo.flarb DROP CONSTRAINT DF__flarb__e__1C722D53 GO CREATE TABLE dbo.Tmp_flarb ( a int NOT NULL, b int NOT NULL, d datetime NOT NULL, c timestamp NOT NULL, e uniqueidentifier NOT NULL ) ON [PRIMARY] GO ALTER TABLE dbo.Tmp_flarb SET (LOCK_ESCALATION = TABLE) GO ALTER TABLE dbo.Tmp_flarb ADD CONSTRAINT DF__flarb__d__1B7E091A DEFAULT (getdate()) FOR d GO ALTER TABLE dbo.Tmp_flarb ADD CONSTRAINT DF__flarb__e__1C722D53 DEFAULT (newsequentialid()) FOR e GO IF EXISTS(SELECT * FROM dbo.flarb) EXEC('INSERT INTO dbo.Tmp_flarb (a, b, d, e) SELECT a, b, d, e FROM dbo.flarb WITH (HOLDLOCK TABLOCKX)') GO ALTER TABLE dbo.blarf DROP CONSTRAINT FK__blarf__a__1E5A75C5 GO DROP TABLE dbo.flarb GO EXECUTE sp_rename N'dbo.Tmp_flarb', N'flarb', 'OBJECT' GO ALTER TABLE dbo.flarb ADD CONSTRAINT PK__flarb__3BD0198EF8B8CFAF PRIMARY KEY CLUSTERED ( a ) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO ALTER TABLE dbo.flarb ADD CONSTRAINT CK__flarb__b__1A89E4E1 CHECK (([b]>(1))) GO CREATE TRIGGER dbo.flarb_tr ON dbo.flarb FOR UPDATE AS SELECT 1; GO COMMIT BEGIN TRANSACTION GO ALTER TABLE dbo.blarf ADD CONSTRAINT FK__blarf__a__1E5A75C5 FOREIGN KEY ( a ) REFERENCES dbo.flarb ( a ) ON UPDATE NO ACTION ON DELETE NO ACTION GO ALTER TABLE dbo.blarf SET (LOCK_ESCALATION = TABLE) GO COMMIT
Yeah, that really looks like something I want to run in production, even if the table is small.
The other alternative is to do this quite manually. Say you have this table:
CREATE TABLE dbo.Employee ( EmployeeID INT, Name NVARCHAR(255), Salary INT ); INSERT ...
Theoretically, and leaving out the complications caused by keys, constraints, triggers, and schemabound objects, you could "change" the order of the columns by - for each column to the left of the one you want to move - creating a new column, moving the data, dropping the old column, and renaming the new column. This works because the new column is always added to the "end" of the table. Leaving out error handling and any of the other complications:
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; BEGIN TRANSACTION; ALTER TABLE dbo.Employee ADD Nametmp NVARCHAR(255); UPDATE dbo.Employee SET Nametmp = Name; ALTER TABLE dbo.Employee DROP COLUMN Name; EXEC sp_rename N'dbo.Employee.Nametmp', N'Name', N'COLUMN'; COMMIT TRANSACTION;
This of course has the potential to be as disruptive (or worse) as the Management Studio approach of just swapping out the entire table, and gets really complicated if you want to move more than one column.
Now, do you really need to change the column order?
Do you want to change the underlying table, or just the resuls?
If it's just the results, then simply re-arrange your select statement.
eg. instead of
SELECT Eid, Ename, Esalary FROM ThatTable;
SELECT Eid, ESalary, EName FROM ThatTable;
You could also setup a view based on that table that selects in the desired order.
And of course if you really need to, you could simply drop and re-create the table. Just make sure to take care of exporting and importing the data if you want to keep it.